SGR 1935+2154

J. R. Cummmings reports on behalf of the Swift-BAT team:

Swift-BAT has observed three additional short, soft events from SGR 1935+2154
(Stamatikos et al. GCN 16520
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 , Lien et al. GCN 16522
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 ).  The first was at
285.8 seconds after the discovery event reported in Stamatikos et al.  The
second was at T+497.4 seconds.  The third was at T+27157 seconds (BAT
trigger # 603514; no automated response occurred since the brightness was
less than the threshold set for retriggering on the known source).

At the time of the earlier two events, Swift had slewed to the source
position, so the source was on axis.  At the time of the later event, the
source was 17% coded in BAT.

The fluences of the earlier events were about 1/3 and 1/5 of the fluence
of the discovery event and were too low to get reliable spectral data.  A
simple power-law fit of the spectrum of the later event has a photon index
of 2.8 � 0.2.  The fluence from 15-150 keV in 0.07 seconds was
(6.1 � 1.2) x 10^-8 ergs/cm^2.

S. Campana (INAF-Brera),  A. de Ugarte Postigo (IAA-CSIC, DARK/NBI),
C. C. Thoene (IAA-CSIC), J. Gorosabel (IAA-CSIC/UPV-EHU),
N. Rea (CSIC-ICE Barcelona) , F. Coti Zelati (Universita` dell'Insubria, 
INAF-Brera)

Swift/XRT observed the new magnetar SGR 1935+2154 (Stamatikos et al. GCN 
16520
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 )
twice before the activation of the source during the monitoring of the 
Galactic plane.

The first observation took place on Dec 30, 2010 for 519 s (obsid 
00045278001).
SGR 1935+2154 is far off-axis and it is barely detected at a rate of
5.4E-03 � 3.9E-03 cts/s (using sosta within XIMAGE
at the enhanced Swift XRT position, Osborne et al. GCN 16521
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 ).

The second observation took place on Aug 28, 2011 for 623 s (obsid 
00045271001).
SGR 1935+2154 is detected at a rate 1.55E-02 � 0.63E-02 cts/s at
RA(J2000)= 19h34m55.75s
Dec(J2000)= 21:53:49.15
with an error radius of 8.6 arcsec.
This position lies at 1.4 arcsec from the enhanced Swift position.

If the source was in quiescence at that time, the outburst showed only an
increase of the persistent flux of a factor of a few.

Y. Kaneko, E. Gogus (Sabanci University), G. Younes (USRA/NASA-MSFC), S.
Guiriec (GSFC/CRESST/UMD), C. Kouveliotou (NASA-MSFC)(Sabanci University),
A. von Kienlin (MPE) report on behalf of the Fermi GBM magnetar team:

We have searched for untriggered events from the newly discovered SGR
1935+2154 using the daily GBM data of 6 days, from July 3 to July 8.  We
identified 3 bursts from the direction of the SGR at the following times
coinciding with the Swift BAT observations (Cummings, GCN 16530
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 ), all on
July 5:

1: 09:32:49 UT (426245572 Fermi MET =  BAT trigger 603488)
2: 09:37:35 UT (426245857 Fermi MET =  Trig+285.8 s)
3: 09:41:07 UT (426246069 Fermi MET = Trig+497.4 s)
We note that the 3rd burst was extremely weak, detected with much lower
significance (<3.5 sigma).  The SGR was not visible to GBM at the time of the
fourth event detected with BAT at Trig+27157 s (426272729 MET).  No other
events from the direction of the SGR were identified in the GBM data at
>4.5-sigma level.

D. N. Burrows (PSU), P. D'Avanzo (INAF-OAB), N. Gehrels (NASA/GSFC),
J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),
F. E. Marshall (NASA/GSFC), T. Sakamoto (AGU) and
B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team:

At 12:16:26 UT and 12:31:11, the Swift Burst Alert Telescope (BAT) triggered
twice on an outburst from SGR 1935+2154 (triggers=632158, 632159).  
Swift slewed immediately to the location. The BAT on-board calculated location 
is RA, Dec 293.724, +21.888 which is 
   RA(J2000) = 19h 34m 54s
   Dec(J2000) = +21d 53' 16"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve for the first trigger
shows a single-peaked structure with a duration of about 0.2 sec.  
The peak count rate was ~3200 counts/sec (15-350 keV), at ~0 sec 
after the trigger.  The second light curve also shows a single-peaked 
structure with a duration of about 0.2 sec.  The peak count rate was 
~11,000 counts/sec (15350 keV), at ~0 sec after the second trigger. 

The XRT began observing the field at 12:17:48.1 UT, 82.0 seconds after
the BAT trigger. Using promptly downlinked data we find an X-ray source 
with an enhanced position: RA, Dec 293.7312, 21.8973 which
is equivalent to:
   RA(J2000)  = 19h 34m 55.50s
   Dec(J2000) = +21d 53' 50.3"
with an uncertainty of 2.5 arcseconds (radius, 90% containment). This
location is 41 arcseconds from the BAT onboard position, within the BAT
error circle. This position is consistent with the XRT position reported 
for this source in Cummings et al. (ATel #6294). This position may be 
improved as more data are received; the latest position is available 
at http://www.swift.ac.uk/sper. We cannot determine whether the source is 
fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 1.27
x 10^22 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 86 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the large, but uncertain extinction expected. 

This source was discovered by Swift in July 5, 2014 (Cummings et al, ATel #6294). 
This is the first activity since that time.

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Swift/BAT triggered twice within 15 minutes on successive outbursts from the 
soft gamma repeater SGR 1935+2154 (Burrows, et al., GCN Circ. 17485
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 ).   These 
were triggers #632158 (trigger 1) and #632159 (trigger 2).

Using the data set from T-61 to T+242 sec for trigger 1 and the data set from 
T-120 to T+183 set
for trigger 2 from the recent telemetry downlinks, we report further analysis of 
the BAT detection of two outbursts from SGR 1935+2154. The BAT ground-calculated 
position from trigger 2 is
RA, Dec = 293.722, 21.889 deg which is
    RA(J2000)  =  19h 34m 53.2s
    Dec(J2000) = +21d 53' 19.1"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 15% for trigger 1 and 100% for trigger 2.

For  trigger 1, the mask-weighted light curve shows a single peak of total 
duration ~100 msec.
T90 (15-350 keV) is 0.08 +- 0.02 sec (estimated error including systematics).  
For  trigger 2,
the mask-weighted light curve shows a single peak of total duration ~20 msec.
T90 (15-350 keV) is 0.02 +- 0.008 sec (estimated error including systematics).

For trigger 1, the time-averaged spectrum from T+0.00 to T+0.09 sec fit by a simple
power-law model shows the power law index of 2.92 +- 0.44 (chi squared 48.50 for 
57 d.o.f.).
The fluence in the 15-150 keV band is 4.6 +- 1.1 x 10^-8 erg/cm2. The 1-sec peak 
photon flux
measured from T-0.45 sec in the 15-150 keV band is 1.3 +- 0.4 ph/cm2/sec.
  A single blackbody fit to the time-averaged spectrum shows the blackbody
temperature of 5.45 +- 1.30 keV (chi squared 50.26 for 57 d.o.f.).
A thermal bremsstrahlung model fit shows the temperature of 22.17 +- 9.67 keV
(chi squared 46.62 for 57 d.o.f.).  A double blackbody fit shows the lower 
temperature
of 4.13 +1.28 keV and the higher temperature of 12.69 (error not unconstrained) keV
(chi squared 44.57 for 55 d.o.f.).  All the quoted errors are at the 90% 
confidence level.

For trigger 2, the time-averaged spectrum from T-0.00 to T+0.02 sec fit by a simple
power-law model shows the power law index of 2.83 +- 0.13 (chi squared 74.87 for 
57 d.o.f.).
The fluence in the 15-150 keV band is 4.4 +- 0.4 x 10^-8 erg/cm2.
The 1-sec peak photon flux measured from T-0.49 sec in the 15-150 keV band
is 0.9 +- 0.1 ph/cm2/sec.  A single blackbody fit to the time-averaged spectrum 
shows the blackbody
temperature of 7.92 +- 0.62 keV (chi squared 63.19 for 57 d.o.f.).
A thermal bremsstrahlung model fit shows the temperature of 28.34 +- 3.59 keV
(chi squared 45.19 for 57 d.o.f.).  A double blackbody fit shows the lower 
temperature
of 4.13 +1.22 keV and the higher temperature of 10.46 (error not unconstrained) keV
(chi squared 42.09 for 55 d.o.f.).  All the quoted errors are at the 90% 
confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/632158/BA/
http://gcn.gsfc.nasa.gov/notices_s/632159/BA/

E. Burns (UAH) and G. Younes (GWU)
report on behalf of the Fermi GBM Team:

"At 17:57:05.99 UT on 22 February 2015, the Fermi Gamma-Ray Burst
Monitor triggered (446320628/150222748) on a burst from
SGR 1935+2154, which was reported to be in outburst by
Burrows et al. (GCN 17485
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 ). The GBM burst occurred over 5 hours
after the bursts detected by the Swift BAT. The GBM on-ground
location is consistent with the known source position.

The burst consists of a single pulse, with a duration of
about 0.05 s. The burst is well-fit with a power law function
with an exponential high-energy cutoff parameterized as
Epeak = 29 +/- 1 keV and an Index -0.25 +/- 0.31. The corresponding
peak flux integrated over 16ms (10-1000 keV) is
(146 +/- 8)E-06 erg/s/cm^2. The fluence during T0-0.048s to
T0+0.000s is (1.6 +/- 0.1)E-07 erg/cm^2. A fit to a double
black-body spectrum is a statistical tie with the exponential
power-law fit, with one extra parameter and blackbody temperatures
of 4.3 +/- 0.7 keV and 10.4 +/- 1.0 keV. The other models reported
in Krimm et al. (GCN 17490
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 ) are not statistically favored.

This burst was followed by four further triggers at
19:44:16.94 UT (trigger 446327059/150222822) on 22 February 2015,
01:38:07.99 UT (446348290/150223068),
05:24:54.16 UT (446361897/150223226), and
06:45:40.13 UT (446366743/150223282) on 23 February 2015,
all consistent with being from SGR 1935+2154.
All of these triggers consist of a single peak. The third trigger,
150223068, is several times more intense than the others, which are
of about equal intensity.

The analysis results presented above are preliminary.

These bursts are bright enough that some are being classified by
the flight software as GRBs. We will correct this classification
in the online catalog at the Fermi Science Support Center:

http://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigtrig.html

but will not issue further circulars to correct the classification."

[GCN OPS NOTE(23feb15):  Per author's request, the date was corrected
in the first line from "23 Feb" to "22 Feb".]

S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks,
D. Svinkin, and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

A bright, short-duration, soft burst has been observed by Konus-Wind, 
INTEGRAL (SPI-ACS), and Mars-Odyssey (HEND), so far, at about 41064 s UT 
(11:24:24) on April 12.

We have triangulated it to a preliminary, 3 sigma error box whose
coordinates are:
---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   293.489 (19h 33m 57s) +22.543 (+22d 32' 35")
  Corners:
   293.060 (19h 32m 14s) +23.547 (+23d 32' 50")
   293.029 (19h 32m 07s) +24.004 (+24d 00' 14")
   293.918 (19h 35m 40s) +21.515 (+21d 30' 54")
   293.951 (19h 35m 48s) +21.033 (+21d 02' 00")
  ---------------------------------------------
The error box area is 1118 sq. arcmin, and its maximum
dimension is 3 deg (the minimum one is 7 arcmin).
The Sun distance was 84 deg.

This box may be improved.

The position of SGR 1935+2154 (Stamatikos et., al. GCN Circ. 16520
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 ; Lien 
et al., GCN Circ. 16522
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 ; Cummmings et al., ATel #6294) is inside the box 
at 41 arcmin from its center (at 0.8 arcmin from the center line of the 
7 arcmin wide Konus-HEND annulus).

Given the positional coincidence of this burst with SGR 1935+2154 and 
softness of its spectrum (as observed by Konus-Wind), we conclude this 
burst is likely originated from SGR 1935+2154.

A triangulation map is posted at
http://www.ioffe.ru/LEA/SGRs/150412_T41064/IPN/

The Konus-Wind time history and spectrum will be given in a forthcoming 
GCN Circular.

S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

A bright, short-duration, soft burst which is likely originated from
SGR 1935+2154 (IPN triangulation: Golenetskii et al., GCN 17699
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 )
triggered Konus-Wind at T0=41064.683 s UT (11:24:24.683).

The light curve shows a single pulse with a sharp(<10 ms) rise
and a total duration of ~1.7 s.
The emission is seen up to ~200 keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/SGRs/150412_T41064/

As observed by Konus-Wind, the burst had a fluence
of 2.60(-0.03,+0.03)x10^-5 erg/cm2, and a 16-ms peak flux,
measured from T0+0.800 s, of 2.3(-0.1,+0.1)x10^-5 erg/cm2/s
(both in the 20 - 200 keV energy range).

The time-averaged spectrum (measured from T0 to T0+9.472 s)
is best fit in the 20 - 250 keV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = +0.21(-0.13,+0.13),
and Ep = 36.5(-0.6,+0.6) keV
(chi2 = 28.6/31 dof).
A double blackbody fit to this spectrum yields
the lower temperature kT1 = 6.4 (-0.7,+0.7) keV and
the higher temperature kT2 = 12.3 (-0.6,+0.7) keV
(chi2=36.3/30 dof).

The rather long duration of the burst along with the
large measured energy fluence put the burst in the class
of "intermediate" SGR bursts.
The measured spectral parameters are in typical range for
bright short and intermediate SGR bursts;
also, they resemble the fits reported by Swift/BAT
and Fermi/GBM for much weaker and shorter bursts detected
during the recent SGR 1935+2154 activity in February, 2015
(Lien et al., GCN 17490
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 ; Burns & Younes, GCN 17496
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 ).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

S. D. Barthelmy (GSFC), J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
T. G. R. Roegiers (PSU) and T. N. Ukwatta (LANL) report on behalf of
the Swift Team:

At 20:49:46 UT, the Swift Burst Alert Telescope (BAT) triggered and
located SGR 1935+2154  (trigger=686443).  Swift slewed immediately to the source.
The BAT on-board calculated location is
RA, Dec 293.704, +21.880, which is
   RA(J2000)  =  19h 34m 49s
   Dec(J2000) = +21d 52' 48"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty).  The BAT light curve shows a single spike
structure with a total duration less than 128 msec.  The peak count rate
was ~3600 counts/sec (15-350 keV), at ~0 sec after the trigger.

The XRT began observing the field at 20:51:05.0 UT, 78.1 seconds after
the BAT trigger. No source was detected in 157 s of promptly downlinked
data. We are waiting for the full dataset to detect and localise the
XRT counterpart.

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 83 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of
the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag.
The 8'x8' region for the list of sources generated on-board covers 100% of the
BAT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the large, but uncertain extinction expected.

P. D'Avanzo (INAF-OAB), P.A. Evans (U Leicester), J. A. Kennea (PSU),
A. Melandri (INAF-OAB), K. L. Page (U Leicester) and
D. M. Palmer (LANL) report on behalf of the Swift Team:

At 09:09:23 UT, the Swift Burst Alert Telescope (BAT) triggered and
located a burst from the Soft Gamma Repeater SGR 1935+2154 
(trigger=686761).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 293.722, +21.891 which is 
   RA(J2000) = 19h 34m 53s
   Dec(J2000) = +21d 53' 28"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed single short spike
of 0.192 ms duration. The peak count rate was 350k counts/s
for 0.064 s, at ~0.1 sec after the trigger. 

The XRT began observing the field at 09:10:22.9 UT, 59.1 seconds after
the BAT trigger. Using promptly downlinked data we find a catalogued
X-ray source located at RA, Dec 293.73098, 21.89458 which is equivalent
to:
   RA(J2000)  = 19h 34m 55.44s
   Dec(J2000) = +21d 53' 40.5"
with an uncertainty of 5.0 arcseconds (radius, 90% containment). This
position may be improved as more data are received; the latest position
is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 1.27
x 10^22 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 64 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the large, but uncertain extinction expected. 

We note that this burst is ~100x brighter in BAT than the burst from
this source 36 hours earlier.

H.-F. Yu (MPE) and P. Veres (UAH) report on behalf of the Fermi GBM Team:

"The Fermi Gamma-ray Burst Monitor (GBM) triggered on 5 events:
485253431/160518359, 485255367/160518382, 485258850/160518422,
485260086/160518436, and 485276375/160518625.

Two of these triggers on 18 May 2016, 485255367/160518382 at 09:09:23.91 UT,
which also triggered Swift/BAT (GCN 19433
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 , D'Avanzo et al.), and
485276375/160518625 at 14:59:31.08 UT, were tentatively classified as GRBs. 
These triggers are in fact due to SGR 1935+2154. 

Further triggers from this source are possible and we will not issue a circular 
for individual triggers from the source, even those that are misclassified as GRBs."

E. Mazaeva (IKI), A. Volnova  (IKI), R. Inasaridze (AbAO), V. Ayvazian 
(AbAO), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger
GRB follow-up collaboration:

We observed the field of SGR 1935+2154 triggered by Swift (Barthelmy et 
al., GCN 19430
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 ; D'Avanzo et al., GCN 19433
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 ) and Fermi (Yu et al., GCN 
19434
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 )  with AS-32 (0.7m) telescope of Abastumani Observatory starting 
on May 16 (UT) 23:26:26. We obtained several unfiltered images of the 
field. We do not detect any source within XRT error circle  (D'Avanzo et 
al., GCN 19433
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 ).

Preliminary photometry of the field is following

Date       UT start   t-T0     Filter  Exp.    UL (3 sigma)
                      (mid, days)       (s)
                      (after GCN 19430
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  trig.)

2016-05-16 23:26:26   0.14112  none    29*60  20.4

We also note a variable star in the field in coordinates (J2000) 
19:34:30.09 +21:52:06.2 and R=15.33 +/- 0.04 which coincides with a star 
of USNO-B1.0 1118-0440363,  R2 = 19.38. The star is not related to the 
SGR 1935+2154.

Photometry is based on nearby USNO-B1.0 stars
USNO-B1.0_id    R2

1119-0448829    14.61
1119-0448214    16.24
1118-0440633    14.34
1118-0440733    14.93

A finding chart can be found at 
http://grb.rssi.ru/SGR1935+2154/SGR1935+2154_20160516_AbAO.png

G. Younes (GWU) reports on behalf of the Fermi/GBM magnetar team:

"Magnetar SGR 1935+2154 is recently undergoing an outburst. The source  
has triggered Fermi/GBM thus far 10 times, starting on 2016 May 14. We  
list below the times of these triggers:

Trigger number        Trigger date        Trigger time (UT)
bn160514349            2016-05-14        08:21:54.66
bn160516868            2016-05-16        20:49:47.00(*)
bn160518359            2016-05-18        08:37:07.59
bn160518382            2016-05-18        09:09:23.91(*)
bn160518422            2016-05-18        10:07:26.79
bn160518436            2016-05-18        10:28:02.84
bn160518625            2016-05-18        14:59:31.08
bn160518648            2016-05-18        15:33:47.01
bn160518709            2016-05-18        17:00:31.76
bn160518820            2016-05-18        19:40:37.47

(*) GBM triggers simultaneous with reported Swift/BAT triggers from
the source

This is the third detected outburst from the source in less than 2
years (July 2014: Cummmings 2014 GCN 16530
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 , Kaneko et al. 2014 GCN
16577
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 ; February 2015: Burrows et al. 2015 GCN 17485
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 , Burns & Younes
2015 GCN 17496
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 ).

Detailed analysis of the FERMI GBM bursts detected during all three
outbursts is underway and will be reported elsewhere.

We strongly encourage multi-wavelength follow-up of the source during
this recent outburst."

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline,
on behalf of the Konus-Wind team, report:

The bright, short-duration burst from SGR 1935+2154
(Swift-BAT trigger #686761: D'Avanzo et al., GCN Circ. 19433
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 ;
Fermi GBM trigger #bn160518382: Younes, GCN Circ. 19437
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 )
triggered Konus-Wind at T0=32964.102 s UT (09:09:24.102).

The burst light curve shows a single pulse with a total
duration of 150 ms. The emission is seen up to ~200 keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/SGRs/160518_T32964/

As observed by Konus-Wind, the burst had a fluence
of 1.62(-0.07,+0.07)x10^-6 erg/cm2, and a 16-ms peak flux,
measured from T0+0.014 s, of 1.53(-0.15,+0.15)x10^-5 erg/cm2/s
(both in the 20 - 200 keV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+0.128 s)
is equally well fit in the 20 - 200 keV range
by a power law with exponential cutoff (CPL) model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
and by a sum of two blackbody functions (2BB).
The CPL model best fit parameters are:
alpha = 0.23 (-0.55,+0.61)
and Ep = 29 (-3,+2) keV (chi2 = 8/15 dof).
The 2BB fit to this spectrum yields
the cool BB temperature kT1 = 4.9 (-2.2,+2.1) keV
and the hot BB temperature kT2 = 9.8 (-1.0,+2.5) keV
(chi2=8/14 dof).

Assuming isotropic emission and  the distance to the source
of 9.1 kpc (Gaensler, GCN Circ.16533
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 ; Pavlovic et al., 2013;
Kozlova et al., 2016, arXiv:1605.02993
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 ), we estimate the
total energy release in the burst E_tot is ~1.6x10^40 erg
and the peak luminosity, L_max, is ~1.5x10^41 erg/s
(both in the 20-200 keV range).

Although this burst is more than order of magnitude less
energetic than the 1.7s-long "intermediate" flare (IF) from
this source on 2015 April 12 (Kozlova et al., 2016), its peak
luminosity is almost comparable to that of the IF.

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

S. D. Barthelmy (GSFC), P. D'Avanzo (INAF-OAB), J. A. Kennea (PSU),
A. Melandri (INAF-OAB), D. M. Palmer (LANL) and T. N. Ukwatta (LANL)
report on behalf of the Swift Team:

At 20:01:47 UT, the Swift Burst Alert Telescope (BAT) triggered on
SGR 1935+2154 (trigger=687123).  Swift slewed immediately to the source. 
The BAT on-board calculated location is 
RA, Dec 293.750, +21.911, which is 
   RA(J2000)  =  19h 35m 00s
   Dec(J2000) = +21d 54' 39"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single spike
with a duration less than 0.128 sec.  The peak count rate
was ~1500 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 20:03:08.8 UT, 81.6 seconds after
the BAT trigger. Using promptly downlinked data we find a catalogued
X-ray source located at RA, Dec 293.73150, 21.89454 which is equivalent
to:
   RA(J2000)  = 19h 34m 55.56s
   Dec(J2000) = +21d 53' 40.3"
with an uncertainty of 4.8 arcseconds (radius, 90% containment). This
position may be improved as more data are received; the latest position
is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 1.27
x 10^22 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 85 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 78% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the large, but uncertain extinction expected.

S. D. Barthelmy (GSFC), P. D'Avanzo (INAF-OAB), J. A. Kennea (PSU),
A. Melandri (INAF-OAB) and D. M. Palmer (LANL) report on behalf of the
Swift Team:

At 20:23:42 UT, the Swift Burst Alert Telescope (BAT) triggered on
SGR 1935+2154 (trigger=687124) while Swift was observing this source. 
Swift slewed immediately to the source. 
The BAT on-board calculated location is 
RA, Dec 293.730, +21.905, which is 
   RA(J2000)  =  19h 34m 55s
   Dec(J2000) = +21d 54' 17"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single spike
with a duration less than 0.128 sec.  The peak count rate
was ~9500 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 20:24:13.7 UT, 31.7 seconds after
the BAT trigger. No source was detected in 315 s of promptly downlinked
data. We are waiting for the full dataset to detect and localise the
XRT counterpart. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 38 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of
the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
BAT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the large, but uncertain extinction expected.

S. Sugita (Tokyo Tech), H. Negoro (Nihon U.),  
S. Ueno, H. Tomida, S. Nakahira, M. Ishikawa, Y. E. Nakagawa, Y. Sugawara (JAXA), 
T. Mihara, M. Sugizaki, M. Serino, W. Iwakiri, M. Shidatsu, J. Sugimoto, T. Takagi, 
M. Matsuoka (RIKEN), N. Kawai, N. Isobe, T. Yoshii, Y. Tachibana, Y. Ono, 
T. Fujiwara (Tokyo Tech), A. Yoshida, T. Sakamoto, Y. Kawakubo, Y. Kitaoka (AGU), 
H. Tsunemi, R. Shomura (Osaka U.), M. Nakajima, K. Tanaka, T. Masumitsu, 
T. Kawase (Nihon U.), Y. Ueda, T. Kawamuro, T. Hori, A. Tanimoto (Kyoto U.), 
Y. Tsuboi, Y. Nakamura, R. Sasaki (Chuo U.), M. Yamauchi, K. Furuya (Miyazaki U.),  
K. Yamaoka (Nagoya U.) report on behalf of the MAXI team:

The MAXI/GSC nova-alert system triggered on a bright short burst at 15:16:35 UT on 2016 Jun 20.
The position is consistent with that of SGR 1935+2154 (see also Stanbro et al. GCN 19544
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 ).
Although the current sky coverage of this burst is by the gas-leaking camera, 
we have tentatively estimated the 2-20 keV flux to be ~80 counts/s (>20 crab).

G. Younes, C. Kouveliotou (GWU) report on behalf of the Fermi/GBM magnetar
team:

"SGR 1935+2154 has triggered FERMI/GBM twice in the past 24 hours on short
bright events. The times of the triggers are as follows:

Trigger number        Trigger date        Trigger time (UT)
bn160620637            2016-06-20        15:16:34.88(*)
bn160618852            2016-06-18        20:27:25.80

(*) GBM trigger simultaneous with MAXI/GSC detection (Negoro et al. 2016,
GCN 19545
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 )

The source has been sporadically undergoing outbursts for the past two
years (see, e.g., Cummmings 2014 GCN 16530
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 , Kaneko et al. 2014 GCN 16577
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 ,
Burrows et al. 2015 GCN 17485
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 , Burns & Younes 2015 GCN 17496
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 , Yu & Veres
2016 GCN 19434
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 , Younes 2016 GCN 19437
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 ).

Detailed analysis of the FERMI GBM triggered and untriggered bursts
detected during all outburst episodes is underway and will be reported
elsewhere."


-- 
George A. Younes, PhD
Postdoctoral Researcher
The George Washington University
Physics department
725 21st St NW, Washington, DC 20052

D. N. Burrows (PSU), A. D'Ai (INAF-IASFPA), N. Gehrels (NASA/GSFC),
C. Gronwall (PSU), J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC) and
A. Maselli (INAF-IASFPA) report on behalf of the Swift Team:

At 19:24:40 UT, the Swift Burst Alert Telescope (BAT) triggered and
located SGR 1935+2154 (trigger=701182).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 293.716, +21.894 which is 
   RA(J2000) = 19h 34m 52s
   Dec(J2000) = +21d 53' 37"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a short spike
with a duration of about 0.1 sec.  The peak count rate
was ~32000 counts/sec (15-350 keV), at ~0.1 sec after the trigger. 

The XRT began observing the field at 19:25:53.6 UT, 73.8 seconds after
the BAT trigger. Using promptly downlinked data we find an
X-ray source with an enhanced position: RA, Dec 293.7324, 21.8956 which
is equivalent to:
   RA(J2000)  = 19h 34m 55.78s
   Dec(J2000) = +21d 53' 44.0"
with an uncertainty of 3.0 arcseconds (radius, 90% containment). This
position is roughly consistent with SGR 1935+2154.  This
position may be improved as more data are received; the latest position
is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 1.27
x 10^22 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 79 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the large, but uncertain extinction expected.

S. D. Barthelmy (GSFC), A. D'Ai (INAF-IASFPA), N. Gehrels (NASA/GSFC),
C. Gronwall (PSU) and D. M. Palmer (LANL) report on behalf of the
Swift Team:

At 13:54:30 UT, the Swift Burst Alert Telescope (BAT) triggered and
located SGR 1935+2154 (trigger=701590).  Swift slewed immediately to the source. 
The BAT on-board calculated location is 
RA, Dec 293.730, +21.884 which is 
   RA(J2000)  =  19h 34m 55s
   Dec(J2000) = +21d 53' 03"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single spike
with a duration of about 0.3 sec.  The peak count rate
was ~416,000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 13:56:19.8 UT, 108.9 seconds after
the BAT trigger. Using promptly downlinked data we find a
X-ray source located at RA, Dec 293.73009, 21.89586 which is equivalent
to:
   RA(J2000)  = 19h 34m 55.22s
   Dec(J2000) = +21d 53' 45.1"
with an uncertainty of 4.1 arcseconds (radius, 90% containment). This is
consistent with the known source SGR 1935+2154.  This
position may be improved as more data are received; the latest position
is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.27 x
10^22 cm^-2, Willingale et al. 2013), with an excess column of 6
(+6.83/-4.97) x 10^22 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 112 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the large, but uncertain extinction expected.

J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
 
Using the data set from T-119 to T+76 sec from the recent telemetry downlinks,
we report further analysis of the bright event from SGR 1935+2154 (trigger #701590)
(Barthelmy, et al., GCN Circ. 19590
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 ).  The BAT ground-calculated position is
RA, Dec = 293.730, 21.887 deg, which is 
   RA(J2000)  =  19h 34m 55.3s 
   Dec(J2000) = +21d 53' 14.6" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 82%.
 
The mask-weighted light curve shows a very rectangular profile starting at ~T-0.15 sec
and ending at ~T+0.7 sec.  T90 (15-350 keV) is 0.680 +- 0.004 sec (estimated error
including systematics).
 
The time-averaged spectrum from T-0.22 to T+0.67 sec best fit by a double blackbody
with a lower temperature of 7.60 +- 0.42 keV and the higher temperature of 14.25 +- 0.89 keV
(chi squared 40.9 for 55 d.o.f.).  For reference, the simple power-law model yields
a power law index of 3.09 +- 0.02 (chi squared 2025 for 57 d.o.f.).
All the quoted errors are at the 90% confidence level.
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/701590/BA/

George Younes (GWU), Chryssa Kouveliotou (GWU), Rachel Hamburg (UAH),
and Eric Burns (UAH) report on behalf of a larger collaboration:

"At 13:54:30.75 UT on 26 June 2016, the Fermi Gamma-Ray Burst
Monitor triggered on a bright, SGR-like burst from the direction of
the magnetar SGR 1935+2154 (trigger 488642074/160626580). This
burst also triggered Swift/BAT (GCN #19590
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 , Barthelmy et al. 2016).

The burst has a duration of T90 ~ 700 +/- 20 ms in the energy range
10-200 keV. It is well-fit by a two blackbody model with temperatures
of kT1 = 8.0 +/- 0.1 keV and kT2 = 14.0 +/- 0.3 keV.  The
corresponding flux  in the energy range 10-200 keV is (2.49 +/-
0.01)E-05 erg/s/cm^2. The peak flux integrated over 16 ms is (3.6 +/-
0.1)E-05 erg/s/cm^2.

We note that the source has been undergoing an outburst since 2016 May
14, with a total of 39 GBM triggers. This is the third activation of the
source following its July 2014 and February 2015 outbursts. The
analysis results presented above are preliminary, and the full
analysis of the bursts from all three outbursts is underway."

-- 
George A. Younes, PhD
Postdoctoral Researcher
The George Washington University
Physics department
725 21st St NW, Washington, DC 20052

K. P. Mooley, T. D. Staley, R. P. Fender (Oxford), T. Cantwell 
(Manchester), C. Rumsey, D. Titterington, S. H. Carey, J. Hickish, Y. C. 
Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. Grainge, A. Scaife 
(Manchester)

We observed SGR 1935+2154 with the AMI Large Array at 15 GHz at several 
epochs, obtaining the following upper limits (3sigma). This magnetar has 
been in outburst since 14 May 2016, with 39 Fermi/GBM triggers (Younes 
et al., GCN 19598
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 ) and at least 7 Swift/BAT triggers (e.g. Barthelmy et 
al., GCN 19590
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 ). The AMI-LA robotically triggered on all the BAT alerts. 
The non-detections in the radio indicate that the magnetar outburst has 
not seen any giant flare similar to SGR 1806-20 in Dec 2004.

---------------------
Date             S
(UT)            (uJy)
---------------------
2016 May 16.98  <282
2016 May 18.21  <144
2016 May 20.22  <108
2016 May 21.27  <147
2016 May 22.07  <129
2016 May 23.12  <204
2016 May 27.17  <111
2016 Jun 25.05  <132
2016 Jun 26.97  <360
---------------------

We thank the AMI staff for scheduling these observations.

D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:

The bright burst from SGR 1935+2154 (Swift detection:
Barthelmy et al., GCN 19590
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 ; Cummings et al., GCN 19596
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 ;
Fermi/GBM detection: Younes et al., GCN 19598
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 )
triggered Konus-Wind at T0=50073.909 s UT (13:54:33.909)
on 2016 June 26.

The light curve shows a single pulse with a sharp rise
and a total duration of ~0.8 s.
The emission is seen up to ~200 keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/SGRs/160626_T50073/

As observed by Konus-Wind, the burst had a fluence
of 1.28(-0.02,+0.02)x10^-5 erg/cm2, and a 16-ms peak flux,
measured from T0, of 2.1(-0.1,+0.1)x10^-5 erg/cm2/s
(both in the 20 - 200 keV energy range).

The burst spectrum (measured from T0 to T0+0.256 s)
is well fit by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.17(-0.16,+0.16),
and Ep = 37.5(-1.1,+1.0) keV
(c-stat = 16.1/25 dof).
A double blackbody function fits this spectrum equally well
(c-stat = 17.3/26 dof), with
the cold BB temperature of 6.6 (-0.6,+0.6) keV and
the hot BB temperature of 13.9 (-0.6,+0.8) keV.

This event continues a series of about a dozen bright bursts
from SGR 1935+2154 detected by Konus-Wind in May-June, 2016.
Varying in their durations and energy fluences,
these bursts demonstrate spectral properties and peak
luminosities similar to those of the 1.7s-long "intermediate"
flare (IF) from this source (Kozlova et al. 2016, MNRAS 460, 2008).

All the quoted errors are at the 1 sigma confidence level.
All the quoted values are preliminary.

Y. Yamada, A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama (AGU),
K. Yamaoka (Nagoya U), S. Nakahira (JAXA), I. Takahashi (IPMU), Y. Asaoka,
S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR),
M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The short burst from SGR 1935+2154 (MAXI, Sugita et al. GCN Circ. 19545
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 ;
Fermi-GBM trigger #488128598; INTEGRAL-ACS trigger #7490) triggered the CALET
Gamma-Ray Burst Monitor (CGBM) at 15:16:38.82 on 20 June 2016.  The burst signal
was only seen by the SGM instrument.

The light curve of the SGM shows a single peak.  The emission starts at T0-0.2 sec and
ends at T0.  The T90 duration measured by the SGM data is 0.16 +- 0.04 sec (40-100 keV).
The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight/1150470954/

Furthermore, we noticed that the following short bursts from SGR 1935+2154
are also seen in the CGBM survey data.

- 2016-06-02 12:19:30 (Fermi-GBM: bn160602514)
- 2016-06-23 21:19:42 (a possible burst; no confirmation by other instrument)
- 2016-06-23 21:23:36 (Fermi-GBM: bn160623891)
- 2016-06-25 08:04:52 (Fermi-GBM: bn160625337)
- 2016-06-26 09:40:12 (Fermi-GBM: bn160626403)

The CGBM data used in this analysis are provided by the Waseda CALET Operation Center
located at the Waseda University.

J.Wood (NASA/MSFC) and E. Bissaldi (Politecnico & INFN Bari)
report on behalf of the Fermi GBM Team:

"At 09:00:53.70 UT on 4 October 2019, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered on a bright, SGR-like burst from the direction of
the magnetar SGR 1935+2154 (trigger 591872458/191004376).

The burst has a duration (T90) of ~0.1 seconds in the energy range 10-300 keV.
It is well-fit by a Comptonized model with Epeak 28.71 +/- 2.71 keV and alpha -0.30 +/- 0.55.

The event fluence (10-300 keV) from T0-0.112s to T0+0.016s is (7.142 +/- 0.576)E-8 erg/cm^2.
The average photon flux in the 10-300 keV band during this period is 14.19 +/- 1.0 ph/s/cm^2.

We note that this is the first outburst since June 2016.
The analysis results presented above are preliminary.

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"

E. Ambrosi (INAF-IASFPA), S. D. Barthelmy (GSFC),
A. D'Ai (INAF-IASFPA), V. D'Elia (SSDC), A. Y. Lien (GSFC/UMBC) and
K. L. Page (U Leicester) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 06:34:00 UT, the Swift Burst Alert Telescope (BAT) triggered and
located SGR 1935+2154 (trigger=933083).  Swift did not slew to the source. 
The BAT on-board calculated location is 
RA, Dec 293.743, +21.896, which is 
   RA(J2000)  =  19h 34m 58s
   Dec(J2000) = +21d 53' 44"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single peak
structure with a duration of about 0.2 sec.  The peak count rate
was ~4500 counts/sec (15-350 keV), at ~0 sec after the trigger. 

Swift did not slew to this source because the merit value of the 
source being observed by Swift was higher than the merit value 
for this known source.

T. N. Ukwatta (LANL) E. Ambrosi (INAF-IASFPA), S. D. Barthelmy (GSFC), 
J. R. Cummings (CPI), H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU), (i.e. the Swift-BAT team):

Using the data set from T-119 to T+183 sec from recent telemetry downlinks,
we report further analysis of the BAT detection of a burst from SGR 1935+2154
(trigger #933083)  (Ambrosi, et al., GCN Circ. 26153
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 ).  The BAT
ground-calculated position is RA, Dec = 293.741, 21.901 deg which is 
  RA(J2000)  =  19h 34m 57.8s 
  Dec(J2000) = +21d 54' 02.7" 
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 85%.

The lightcurve consists of a single peak with a total duration of ~0.04 sec.
T90 (15-350 keV) is 0.03 +- 0.01 sec (estimated error including systematics).

The time-averaged spectrum from T-0.00 to T+0.04 sec fit by a simple
power-law model shows the power law index of 2.67 +- 0.31 (chi squared 38.4 for 57 d.o.f.).
The fluence in the 15-150 keV band is 2.4 +- 0.4 x 10^-8 erg/cm2.
The 1-sec peak photon flux measured from T-0.48 sec in the 15-150 keV band
is 0.8 +- 0.2 ph/cm2/sec.

A single blackbody fit to the time-averaged spectrum shows the blackbody
temperature of 6.16 +- 0.86 keV (chi squared 36.86 for 57 d.o.f.).
A thermal bremsstrahlung model fit shows the temperature of 24.16 +- 7.80 keV
(chi squared 36.5 for 57 d.o.f.).  A double blackbody fit shows the lower temperature
of 5.78 +0.95 keV and the higher temperature of 52.64 -7.00 keV
(chi squared 30.61 for 55 d.o.f.).  All the quoted errors are at the 90% confidence level. 

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/933083/BA/

E. Ambrosi (INAF-IASFPA), V. D'Elia (SSDC), J. A. Kennea (PSU) and
D. M. Palmer (LANL) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 00:08:58 UT, the Swift Burst Alert Telescope (BAT) triggered and
located a burst from the Soft Gamma Repeater SGR 1935+2154 (trigger=933276). 
Swift did not slew to this burst due to merit compared with the 
pre-planned target.  The BAT on-board calculated location is 
RA, Dec 293.743, +21.915 which is 
   RA(J2000) = 19h 34m 58s
   Dec(J2000) = +21d 54' 54"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a short peak
structure with a duration of about 0.5 sec.  The peak count rate
was ~19000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

This source has resumed activity 2019-11-04 UT with recent bursts listed in:
Ambrosi, et al., GCN Circ. 26153
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   (1 burst)
von Kienlein et al. GCN Circ. 26163
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   (6 bursts)
B. Mailyan et al. GCN 26166
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and previously unreported BAT bursts at 
2019-11-04T01:54:37
2019-11-04T14:47:29
2019-11-04T14:53:05

E. Ambrosi (INAF-IASFPA), V. D'Elia (SSDC), J. A. Kennea (PSU) and
D. M. Palmer (LANL) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 01:36:25 UT, the Swift Burst Alert Telescope (BAT) triggered and
located a burst from SGR 1935+2154 (trigger=933285).  
Swift did not slew due to merit considerations. 
The BAT on-board calculated location is 
RA, Dec 293.753, +21.896 which is 
   RA(J2000) = 19h 35m 01s
   Dec(J2000) = +21d 53' 46"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single peak
structure with a duration of about 0.5 sec.  The peak count rate
was ~130,000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The BAT software is designed to automatically set the trigger of each
known source to twice the intensity seen with the previous trigger. 
Thus, each GCN notice for retriggering on the source indicates a burst
at least twice as bright as the previous burst.  

In this case, the burst is about 7x as bright as reported in GCN 26169
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 . 
This is the brightest burst seen so far in the the current activation 
of this source.

A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

Since the renewal of bursting activity of the SGR 1935+2154
on October 4 (Wood & Bissaldi et al., GCN 25975
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 ,
Ambrosi et al., GCN 26153
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 , GCN 26169
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 , GCN 26171
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 ;
Burgess et al., GCN 26160
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 ; Ukwatta et al., GCN 26162
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 ;
von Kienlin, GCN 26163
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 ) Konus-Wind have triggered on
two bursts from this source.

The following is a list of the Konus-Wind triggers with preliminary
estimates of the burst fluences and peak fluxes.
------------------------------------------------------------------
  Date         T0(KW) s UT                  Fl*           PF**
------------------------------------------------------------------
20191104 38666.612 s UT(10:44:26.612)  1.33 +/-0.07  17.0 +/-1.6
20191105 22268.832 s UT(06:11:08.832)  4.85 +/-0.15  29.4 +/-1.9
------------------------------------------------------------------
*  -  Fluence (20-200 keV) in units of 1e-6 erg/cm2

** - Peak Flux (20-200 keV) on 16-ms time scale
        in units of 1e-6 erg/cm2/s

The time-averaged spectra of the bursts are well fit in the
20 - 200 keV range by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with the following parameters:
-------------------------------------------------------------
#   Tbeg-Tend         alpha            Ep(keV)    chi2/dof
-------------------------------------------------------------
1   0 - 0.128    0.47(-0.81,+0.91)    35(-4,+3)     6/13
2   0 - 0.192   -0.29(-0.34,+0.36)    42(-2,+2)     25/19
-------------------------------------------------------------
In terms of spectral parameters and peak fluxes these bursts are
very similar to the intermediate flare from SGR 1935+2154 (Kozlova et 
al.,
MNRAS 460 2, 2016) and, assuming also their durations and fluences,
are typical of short bursts detected by KW during the previous 
activation
of the source.

The Konus-Wind light curves of the bursts are available at
http://www.ioffe.ru/LEA/SGRs/191104_T38666/
http://www.ioffe.ru/LEA/SGRs/191105_T22268/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Ridnaia,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN, and

A. Goldstein, M. S. Briggs, and C. Wilson-Hodge
on behalf of the Fermi GBM team, report:

A bright, short-duration, soft burst has been observed by
Fermi (GBM trigger 608204639) and Konus-Wind,
so far, at about 35034 s UT (09:43:54) on April 10.

We have triangulated it to a Konus-GBM annulus centered at
RA(2000)=355.993 deg (23h 43m 58s) Dec(2000)=-0.325 deg (+0d 19' 31"),
whose radius is 64.478 +/- 0.078 deg (3 sigma).

This localization may be improved.

The position of SGR 1935+2154 is inside the annulus
at 4.2 arcmin from its center line.

Given the positional coincidence of this burst with SGR 1935+2154,
its time history, and softness of its spectrum (as observed by Konus-
Wind and Fermi-GBM), we conclude this burst is likely originated from
SGR 1935+2154.

A triangulation map is posted at
http://www.ioffe.ru/LEA/SGRs/200410_T35032/IPN/

The time history and spectrum will be given in forthcoming GCN Circulars.

P. Veres (UAH), E. Bissaldi (Politecnico and INFN Bari) and M. S. Briggs
(UAH)
report on behalf of the Fermi GBM Team:

"At 09:43:54.30 UT on 10 April 2020, the Fermi Gamma-Ray Burst Monitor
(GBM) triggered
and located an outburst from SGR 1935+2154 (trigger 608204639 / 200410405)
which was also detected by the Konus-Wind (IPN) (Svinkin at al., GCN
27527
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 ). The GBM on-ground location is consistent with the known position of
the SGR.

The trigger was classified as a GRB by the flight software, but it is in
fact from SGR 1935+2154.

The angle from the Fermi LAT boresight at the GBM trigger time is 105
degrees.

The light curve shows a short bright peak with a duration (T90) of about
128 ms (50-300 keV).
The time-averaged spectrum from T0-64 ms to T0+192 ms is best fit by a
power law function with an exponential high-energy cutoff.  The power law
index is 0.70 +/- 0.10 and the cutoff energy, parameterized as Epeak, is
32.7 +/- 0.3 keV

The event fluence (10-1000 keV) in this time interval is (2.57 +/- 0.03)E-6
erg/cm^2. The 64-ms peak photon flux measured starting from T0 in the
10-1000 keV band is 489 +/- 9 ph/s/cm^2.

We note that we see indications of saturation of only the TTE data at the
brightest part of the pulse.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support
Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"

A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

The bright burst from SGR 1935+2154
(IPN triangulation: Svinkin et al., GCN Circ. 27527
Loading...
 
 ,
Fermi GBM observation: Veres et al., GCN Circ. 27531
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 )
triggered Konus-Wind at T0=35032.256 s UT (09:43:52.256)
on 2020 April 10.

The light curve shows a single pulse with a sharp rise
and a total duration of ~0.2 s.
The emission is seen up to ~200 keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/SGRs/200410_T35032/

As observed by Konus-Wind, the burst
had a fluence of 1.55(-0.08,+0.08)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0-0.054 s,
of 1.54(-0.15,+0.15)x10^-5 erg/cm2/s
(both in the 20 - 200 keV energy range).

The burst spectrum (measured from T0 to T0+0.128 s)
is well fit by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.15(-0.85,+0.99)
and Ep = 28(-7,+4) keV (chi2 = 15/14 dof).
A double blackbody function fits this spectrum equally well
(chi2 = 15/13 dof), with
the cold BB temperature of 6.9 (-4.6,+1.4) keV and
the hot BB temperature of 13.0 (-3.6,+7.8) keV.

Although this burst is more than order of magnitude less
energetic than the 1.7s-long "intermediate" flare (IF) from
this source on 2015 April 12 (Kozlova et al. 2016, MNRAS 460,
2008), its peak luminosity is almost comparable to that of the IF.

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. V. Golovin, A. S. Kozyrev, M. L. Litvak,
and A. B. Sanin, on behalf of the HEND-Odyssey GRB team,

A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

S. Barthelmy, J. Cummings, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team, and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

A bright, short-duration, soft burst
(CALET-GRBM detection: Cherry et al., GCN Circ. 27623
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 )
was detected by Konus-Wind, INTEGRAL (SPI-ACS),
Mars-Odyssey (HEND), CALET(GBM), and Swift (BAT)
at about 31997 s UT (08:53:17) on April 22.
The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
 ---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
  293.773 (19h 35m 05s) +21.942 (+21d 56' 31")
 Corners:
  293.559 (19h 34m 14s) +21.634 (+21d 38' 02")
  293.555 (19h 34m 13s) +21.991 (+21d 59' 27")
  293.988 (19h 35m 57s) +22.248 (+22d 14' 52")
  293.990 (19h 35m 58s) +21.893 (+21d 53' 33")
 ---------------------------------------------
The error box area is 517 sq. arcmin, and its maximum
dimension is 44 arcmin (the minimum one is 18 arcmin).
The Sun distance was 91 deg.

This box may be improved.

The position of SGR 1935+2154 is inside the box
at 3.5 arcmin from its center.

Given the positional coincidence of this burst with
SGR 1935+2154 (initially suggested in GCN Circ. 27623
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 ),
its time history, and softness of its spectrum (as observed
by Konus-Wind), we conclude that this burst is likely originated
from SGR 1935+2154.
we conclude THAT this burst
A triangulation map is posted at
http://www.ioffe.ru/LEA/SGRs/200422_T31996/IPN/

The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.

A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

The bright burst from SGR 1935+2154
(CALET-GRBM detection: Cherry et al., GCN Circ. 27623
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 ;
IPN triangulation: Hurley et al., GCN Circ. 27625
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 )
triggered Konus-Wind at T0=31996.933 s UT (08:53:16.933)
on 2020 April 22.

The light curve shows a single pulse with a sharp rise
and a total duration of ~0.6 s.
The emission is seen up to ~250 keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/SGRs/200422_T31996/

As observed by Konus-Wind, the burst
had a fluence of 1.15(-0.03,+0.03)x10^-5 erg/cm2,
and a 16-ms peak flux, measured from T0+0.072 s,
of 2.75(-0.23,+0.23)x10^-5 erg/cm2/s
(both in the 20 - 200 keV energy range).

The burst spectrum (measured from T0 to T0+0.256 s)
is well fit by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.06(-0.24,+0.25)
and Ep = 52(-2,+2) keV (chi2 = 30/25 dof).

A double blackbody function fits this spectrum less well
(chi2 = 40/24 dof), with
the cold BB temperature of 9.4 (-4.5,+1.9) keV and
the hot BB temperature of 18.9 (-3.7,+5.3) keV.

Among 17 bright bursts from SGR 1935+2154 detected by KW
so far this event is the second most fluent (after
the April 12, 2015 Intermediate Flare; Kozlova et al. 2016,
MNRAS 460, 2008) and the second most luminous (after
the November 5, 2019 burst; Ridnaia et al., GCN 26242
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 ).
Also, the spectrum of the burst is characterized by the
hardest peak energy so far; a typical Ep(CPL) for the
KW sample is in the 30-40 keV range.

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

S. D. Barthelmy (GSFC), M. G. Bernardini (INAF-OAB),
P. D'Avanzo (INAF-OAB), J.D. Gropp (PSU), J. A. Kennea (PSU),
A. Y. Lien (GSFC/UMBC), A. Melandri (INAF-OAB), D. M. Palmer (LANL),
T. Sbarrato (INAF-OAB) and M. H. Siegel (PSU) report on behalf of the
Neil Gehrels Swift Observatory Team:

At 18:26:20 UT, the Swift Burst Alert Telescope (BAT) triggered and
located a burst from the Soft Gamma Repeater SGR 1935+2154 (Trigger #968211). 
Because this is a known source Swift did not automatically slew.  
The on-board location is
RA, Dec 293.735, +21.895 which is 
   RA(J2000) = 19h 34m 56s
   Dec(J2000) = +21d 53' 43"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single
64 ms bin with a peak count rate of 25k counts/sec (15-350 keV),
at the time of the trigger. 

A second BAT trigger from this source was seen at 18:32:59 
(trigger #968212) with comparable intensity. 

Follow-up observations with Swift are planned.

C. Fletcher (USRA) reports on behalf of the Fermi GBM Team:

"At 18:26:20.16 UT on 27 April 2020, the Fermi Gamma-Ray Burst
Monitor triggered on a bright, SGR-like burst from the direction
of the magnetar SGR 1935+2154 (trigger 609704785/ 200427768),
which was also detected by the Swift/BAT (Barthelmy et al. 2020, GCN 27657
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 ).

The burst has a duration (T90) of ~2 seconds in the energy range 10-200 keV.

It is well-fit by a power law function with an exponential
high-energy cutoff. The power law index is 0.02 +/- 0.68 and
the cutoff energy, parameterized as Epeak, is 27.2 +/- 2.5 keV.

The event fluence (10-200 keV) from T0-1.024 to T0+1.024 is (2.0 +/- 0.2)E-7 erg/cm^2.
The average photon flux in the 10-200 keV band during this period is 2.5 +/- 0.2
ph/s/cm^2.

Fermi GBM also subsequently triggered on multiple bursts from SGR 1935+2154 on
27 April 2020 with a fraction of these being misclassified as GRBs.

The spectral analysis results presented above are preliminary.

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/�

Y. Sugawara, S. Nakahira (JAXA), H. Negoro, M. Nakajima (Nihon U.), M. Serino (AGU),
M. Aoki, K. Kobayashi, R. Takagi, K, Asakura, K, Seino, S. Mokumoto (Nihon U.),
T. Mihara, C. Guo, Y. Zhou, T. Tamagawa, M. Matsuoka (RIKEN),
T. Sakamoto, S. Sugita, H. Nishida, A. Yoshida (AGU),
Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, Y. Okamoto, S. Kitakoga (Chuo U.),
M. Shidatsu (Ehime U.),
N. Kawai, R. Adachi, M. Niwano (Tokyo Tech),
S. Ueno, H. Tomida, M. Ishikawa, M. Tominaga, T. Nagatsuka (JAXA),
Y. Ueda, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake (Kyoto U.),
H. Tsunemi (Osaka U.),
M. Yamauchi, K. Kurogi, K. Miike (Miyazaki U.),
T. Kawamuro (NAOJ),
K. Yamaoka (Nagoya U.),
Y. Kawakubo (LSU),
M. Sugizaki (NAOC)
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered on two bright short bursts from the position consistent with that of an active Soft Gamma Repeater SGR 1935+2154 (GCN #27657
Loading...
 
 , #27659
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 , Atel #13675).

Showing a double-peaked profile, the first one started at 20:01:45.99 of 2020-04-27 UT with a total duration of ~100 ms.
The 5ms peak flux was about 75 Crab in the 2-20 keV band for each pulse.
The second burst started at 21:56:02.63 UT with a single-peaked structure with a duration of 50 ms. This peak flux was about 40 Crab in 5 ms.

L. Lin (BNU), S. M. Jia, S. N. Zhang (IHEP), 

report on behalf of the Insight-HXMT team:




Since 18:26:20.16 UT on 27 April 2020, Multiple SGR-like bursts have 

been observed by Swift/BAT and Fermi/GBM from magnetar SGR 1935+2154

(Barthelmy et al. 2020,GCN 27657 and Fletcher et al. 2020, GCN 27659
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 ).

And more bursts are coming in (Palmer et al. 2020, GCN 27660
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 ). 




Insight-HXMT is going to continuously observe SGR 1935+2154 for 60 ks

from 2020-04-28 UTC 07:14:52 to 2020-04-29 UTC 11:53:01, with all its

three sets of collimated detectors covering 1-15 keV, 5-30 keV and 

20-250 keV, respectively. The net observing time intervals (in UT) 

without the Earth blockage of SGR 1935+2154 are as following:




2020-04-28 07:27:03      2020-04-28 08:28:32

2020-04-28 09:02:27      2020-04-28 10:03:55

2020-04-28 10:37:52      2020-04-28 11:39:18

2020-04-28 12:13:17      2020-04-28 13:14:41

2020-04-28 13:48:42      2020-04-28 14:50:04

2020-04-28 15:24:07      2020-04-28 16:25:27

2020-04-28 16:59:31      2020-04-28 18:00:50

2020-04-28 18:34:56      2020-04-28 19:36:13

2020-04-28 20:10:21      2020-04-28 21:11:36

2020-04-28 21:45:45      2020-04-28 22:46:58

2020-04-28 23:21:10      2020-04-29 00:22:21

2020-04-29 00:56:35      2020-04-29 01:57:44

2020-04-29 02:31:59      2020-04-29 03:33:07

2020-04-29 04:07:24      2020-04-29 05:08:30

2020-04-29 05:42:49      2020-04-29 06:43:53

2020-04-29 07:18:13      2020-04-29 08:19:16

2020-04-29 08:53:38      2020-04-29 09:54:39

2020-04-29 10:29:02      2020-04-29 11:30:02




SGR 1935+2154 went into outbursts in 2014 July, 2015 Feb., 2016 May 

and June (Lin et al. 2020). Several short bursts including very 

bright ones were detected in 2019 November and 2020 April by multi 

instruments. The source is now in a very active episode. 




We encourage multi-waveband follow up observations from both ground 

and space, especially the observations overlapping with Insight-HXMT. 




Insight-HXMT is the first Chinese space X-ray telescope, which was 

funded jointly by the China National Space Administration (CNSA) and 

the Chinese Academy of Sciences (CAS). 

More information about it could be found at: 

http://www.hxmt.org.

S. Ricciarini (U of Florence),
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),
N. Cannady (GSFC/UMBC), M. L. Cherry (LSU),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The CALET Gamma-ray Burst Monitor (CGBM) has been observing
high bursting activity of SGR 1935+2154 since the CGBM trigger
at ~18:32 UTC on 27 April 2020.
No real-time CGBM GCN notice was distributed about this trigger because
the real-time communication from the ISS was off (loss of signal).
This trigger followed the Swift and Fermi-GBM triggers on bursts
from SGR 1935+2154 at ~18:20 UTC reported in GCNs 27657
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 , 27659
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 , and 27660
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(at this time CGBM HV was off).
The CGBM data display a burst cluster along with multiple
short bright bursts.

The first CGBM trigger was shortly followed by another CGBM trigger at
18:46:08.675 UTC (trigger 1272047979:
http://cgbm.calet.jp/cgbm_trigger/flight/1272047979/index.html)
with several intense bursts.

Additional two unalerted CGBM triggers with multiple short intense soft
bursts were detected at ~20:15 UTC and ~21:49 UTC on 2020-04-27.
After this, CGBM on-board trigger was disabled because it reached the
maximum numbers of the accepted triggers.

Further episodes of SGR activity were observed in CGBM TH data at
~23:18 UTC on 2020-04-27 and at ~00:43 - 00:57 UTC on 2020-04-28.

Totally several tens of short bright SGR bursts have been detected by CGBM
so far. So, SGR 1935+2154 did enter a new phase of activity
as was suggested in GCN 27623
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 .

A. Marathe (NITK), V. Shenoy, V. Bhalerao (IITB), D. Bhattacharya (IUCAA), S. Vadawale (PRL), A. R. Rao (TIFR) report on behalf of the CZTI collaboration:

Investigation of time series data over the last two days reveals the clear detections of multiple bursts in the data, originating from a direction consistent with outbursting SGR 1935+2154 (GCNs 27663
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 , 27661
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 , 27660
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 , 27659
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 , 27657
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 , 27631
Loading...
 
 , 27625
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 , 27623
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 , 27554
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 , 27531
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 , 27527
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 ). Owing to the limited localisation abilities of CZTI, we limit this report to bursts reported by other instruments. We see the following clear detections (UTC):

2020-04-27 at 18:32:59
2020-04-27 at 20:15:20
2020-04-28 at 00:44:07

Further analysis of data is under way. The source is close to the plane of detectors (angle from boresight, theta = 95 degrees), hence the incident photons are heavily reprocessed by the satellite before being incident on the detector. Any source spectrum inferences are unlikely.

A Forest of Bursts from SGR 1935+2154


David M. Palmer (LANL) reports on behalf of the BAT Team:



At 18:26:20 of 2020-04-27 UT, the Swift Burst Alert Telescope (BAT)

triggered and located a burst from the Soft Gamma Repeater SGR 1935+2154

(Trigger #968211) (GCN #27657
Loading...
 
 ; Barthelmy et al.). This burst, and many

subsequent bursts described below, continuing to at least T+7 hours (the

time of this writing) were also seen by Fermi/GBM (GCN #27659
Loading...
 
 ; Fletcher

et al.)



This initial burst was followed by an intense sequence of bursts

starting at ~T+300s after the first trigger time. This includes two

separate time segments, 3 seconds and 15 seconds long, made up of rapid

sequences of multiple bursts during which the count rate never returns

to baseline on the 64 ms timescale (the highest time-resolution data

that has been downlinked so far).



During those time intervals, the peak count rate reaches up to 130k

counts/s on a 64 ms timescale over the 15-350 keV band, and 350k

counts/s on a 1 second timescale over the full detector sensitivity

range. (The majority of these additional counts would be below the 15 keV 

calibrated energy bin but above the Low-Level-Discriminator level.

This LLD level varies from detector-to-detector in BAT's 32k-element

array, but is typically 12-14 keV. This indicates that the emission

spectrum is very steep around those energies.)



During the first 24 minutes of the episode, there were at least 35

clearly-distinguishable bursts outside of the piled-up time intervals.



This is similar to the forests of bursts seen 2006-03-29 from 

SGR 1900+14 (Israel et al, 2008, ApJ 685:1114) and 2008-05-28 from

SGR 1627-41. (GCN #7777
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 ; Palmer et al.).



SGR 1935+2154's recent activation was first detected with a burst 5 days

earlier, which was seen by multiple spacecraft, providing timing

information that identified the location to be this source (GCN #27625
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 ;

Hurley et al.). The previous BAT detection was 9 bursts in ~24 hours in

November 2019.





Note: A draft copy of this report was accidentally distributed to the 

GCN (as #27660) before the final version was submitted to ATel, 

and then as this courtesy copy to GCN.  The ATel #13675 submission

is the citable publication of record.

A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

The onset of a new period of activity of SGR 1935+2154
(Swift-BAT detection: Barthelmy et al., GCN Circ. 27657
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 ,
Palmer, GCN Circ. 27665
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 ;
Fermi-GBM observation: Fletcher, GCN Circ. 27659
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 ;
MAXI-GSC detection: Sugawara et al., GCN Circ. 27661
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 ;
CALET-GBM observation: Ricciarini et al., GCN Circ. 27663
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 ;
AstroSat-CZTI detection: Marathe et al., GCN Circ. 27664
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 )
has been detected by Konus-Wind on 2020 April 27.

A series of several tens of bursts triggered Konus-Wind at
66696.729 s UT (18:31:36.729). The series consists of
two very crowded clusters:
from -0.252 s to 8 s and
from 77 s to 116 s relative to the trigger time
(numerous weaker bursts are seen between intense bursts).

The most intense episode of the cluster started at ~85 s
after trigger time. It had a duration of ~23.6 s,
a fluence of 1.09(-0.02,+0.02)x10^-4 erg/cm2,
and a 64-ms peak flux, measured from T0+95.680 s,
of 2.28(-0.27,+0.29)x10^-5 erg/cm2/s
(both in the 20 - 200 keV energy range).

The time-integrated spectrum of this cluster
(measured from T0+74.496 to T0+91.392)
is well fit by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.48(-0.17,+0.18)
and Ep = 35(-1,+1) keV (chi2 = 47/29 dof).
A double blackbody function fits this spectrum equally well
(chi2 = 38/28 dof), with
the cold BB temperature of 4.7 (-0.5,+0.6) keV and
the hot BB temperature of 12.5 (-0.4,+0.5) keV.

The Konus-Wind light curve of this trigger is available at
http://www.ioffe.ru/LEA/SGRs/200427_T66696/

Further SGR 1935+2154 bursts have triggered KW on 2020
April 27, so far, at 71024.348 s UT (19:43:44.348),
79162.174 s UT (21:59:22.174), and 85471.654 s UT
(23:44:31.654).

This burst cluster resembles the series of bursts from
SGR 1900+14 and SGR 1806-20 detected about three months
before giant flares from these sources observed on
1998 August 27 and 2004 December 27, respectively
(Aptekar et al., ApJSS v. 137, p. 227, 2001, Golenetskii
et al., GCN Circ. 2769
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 , Golenetskii et al., GCN Circ. 2896
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 ).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

S. Mereghetti (INAF, IASF-Milano), V. Savchenko (ISDC, Versoix), D. Gotz
(CEA, Saclay), L. Ducci, C. Ferrigno, E. Bozzo (ISDC, Versoix), J.Borkowski
(CAMK, Torun) and A. Bazzano (INAF, IAPS-Roma) report


A bright short burst has been detected by IBAS in the IBIS/ISGRI data at
14:34:24 UT of April 28 (Alert Packet n. 8611), and promptly identified as
originating from the currently active SGR 1935+2154 (GCN #27667
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 , #27666
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 ,
#27665
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 , #27664
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 , #27663
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 , #27662
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 , #27661
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 , #27659
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 , #27657
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 , #27631
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 , ATel
#13682, #13679, #13678, #13675).  Note that the above time is not corrected
for the light-travel but it is consistent with  the one of the radio  burst
from the same source reported in ATel #13681, #13684.

The burst was at an off-axis angle of 8.1 degrees, in the field of view of
the IBIS and SPI instruments, but outside those of JEM-X and OMC.

A preliminary analysis indicates that the burst had a duration of about 0.3
s,  a fluence of 3.9+/-0.2e-7 erg/cm2 in the 25-80 keV range  and a peak flux of
1.2+/-0.1 e-6 erg/cm2/s on 10 ms timescale.

The burst  was also marginally detected in the SPI-ACS  with S/N=4.65 on a
 0.65s time scale. The ACS observation independently gives a  FAP at the
level of 0.0019 (2.9 sigma).

We note that another weaker burst from SGR 1935+2154, lasting about 0.1 s
was  detected  by IBAS at 09:51:05 UT of April 28 (Weak Alert Packet n.
8610).

ISGRI and SPI-ACS lightcurves of the bright event are available at:

https://www.isdc.unige.ch/integral/ibas/cgi-bin/ibas_acs_web.cgi/?trigger=2020-04-28T14-34-23.4100-00000-00000-0

[GCN OPS NOTE(29apr20): Per author's request, the fluence in the 3rd paragraph
was changed from "3.9+/-0.2e-5" to "3.9+/-0.2e-7 erg/cm2" (ie the value
went down by 100x and units were added.  A thank-you to V.Palshin
for pointing out the typo.]

A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

The short burst from SGR 1935+2154
(INTEGRAL detection: Mereghetti et al., GCN Circ. 27668
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 ,
Atel #13685; AGILE detection: Tavani et al., Atel #13686)
triggered Konus-Wind at T0=52464.084 s UT (14:34:24.084)
on 2020 April 28. The burst Earth-crossing time,
T0Earth = 52464.444 s UTC (14:34:24.444), is consistent
with the radio burst from SGR 1935+2154 reported in
Scholz, ATel #13681 and Bochenek et al., Atel #13684.

The light curve shows a multipeaked structure
started at ~T0-0.2 s with a total duration of ~0.5 s.
The emission is seen up to ~250 keV.

The Konus-Wind light curve of this burst is available at
http://www.ioffe.ru/LEA/SGRs/200428_T52464/

As observed by Konus-Wind, the burst
had a fluence of 7.63(-0.75,+0.75)x10^-7 erg/cm2,
and a 16-ms peak flux, measured from T0+0.004 s,
of 9.10(-2.29,+2.29)x10^-6 erg/cm2/s
(both in the 20 - 200 keV energy range).

The burst spectrum (measured from T0 to T0+0.256 s)
is well fit by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.52(-0.50,+0.57)
and Ep = 82(-9,+12) keV (chi2 = 14/24 dof).

A double blackbody function fits this spectrum equally well
(chi2 = 15/23 dof), with
the cold BB temperature of 9.9 (-4.3,+3.9) keV and
the hot BB temperature of 27.4 (-5.1,+9.2) keV.

The burst temporal structure and hardness differ from a
typical SGR burst and resemble the short hard bursts
(Ep ~ 80 - 100 keV) associated with SGR 1900+14,
observed on 1998 October 22 at 15:40:47.4 UT and on
1999 January 10 at 08:39:01.4 UT (Woods et al., ApJL 527,
47, 1999, Aptekar et al., ApJSS 137, 227, 2001), suggesting
a possibly different emission mechanism of such SGR bursts.

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

V. Lipunov, K.Zhirkov, V.Kornilov, E. Gorbovskoy, O.Gress, N.Tiurina,P.Balanutsa,A.Kuznetsov,
F.Balakin,V.Vladimirov, D. Vlasenko, E.Minkina, I.Gorbunov, A.Chasovnikov, A.Pozdnyakov, D.Zimnukhov, V.Senik, 
T.Pogrosheva,D.Kuvshinov, V.Shumkov (Lomonosov Moscow State University, SAI, Physics Department),
R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias),
D. Buckley(South African Astronomical Observatory),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
R. Podesta, C.Lopez, F. Podesta, C.Francile(Observatorio Astronomico Felix Aguilar OAFA),
H. Levato(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),
N.M. Budnev, O.Ershova (Irkutsk State University, API),
V. Yurkov, A. Gabovich, Yu. Sergienko(Blagoveschensk Educational State University)


MASTER Global Robotic Net (http://observ.pereplet.ru,Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)
started SGR 1935+2154 (Barthelmy et al., GCN 27657
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 , 19
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 h 34m 56s +21d 53' 43", er.b. 3')
error-box observations at 2020-04-27 21:57:38UT (3.5h after Swift trigger).

MASTER-Tavrida observed it since 2020-04-27 21:57:38UT to 2020-04-28 00:32:48UT with
unfiltered mlim=20.0m
(observations began at altitute 26deg, the sun  altitude was -31deg.)

MASTER-SAAO observed error-box since 2020-04-28 00:34:53 (target 
altitude 18deg, Sun alt.-57deg) to 2020-04-28 04:03:37UT with 
unfiltered mlim~19-20.2

MASTER-IAC observed error-box 1.5h since 2020-04-28 04:12:42 (target 
altitude = 66deg, sun alt.-23deg)  with unfiltered mlim=19.7-20.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/event.php?id=1345392

The next alert of this SGR was from Integral (trigger time 2020-04-28 
14:34:24 UT, Mereghetti et al. GCN 27668
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 )

MASTER-Amur and MASTER-Tunka observed it automatically started
at 14:34:46UT (22s after trigger time) and at 2020-04-28 14:40:28 UT, 
Lipunov et al. GCN 27666
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 . 
Real time updated cover map and possible OT will be available at:
https://master.sai.msu.ru/site/master2/observ.php?id=1345998

Zhang S.-N., Xiong S.-L., Li C.-K., Li X.-B., Tuo Y.-L., Ge M.-Y.,
Zhao X.-F., Xiao S., Jia S.-M., Nie J.-Y., Zhao H.-S., Luo Q., Li B.,
Cai C., Tan Y., Xue W.-C., Lu F.-J., Song L.-M., Liu C.-Z., Chen Y.,
Cao X.-L., Xu Y.-P., Li T.-P. (IHEP), Lin L. (BNU), Zhang B. (UNLV),
on behalf of the Insight-HXMT team:

Here we report a refined analysis of the Insight-HXMT light curves,
which have been corrected for data saturation and dead-time effects.
Insight-HXMT light curves could be found at:
http://newshxmt.ihep.ac.cn/images/grb/SGR1935_3rd_atel.png

The light curve in LE (1-10 keV) consists of two major bumps with a
separation time of about 0.2 s. The first major bump in LE seems
much brighter and wider than that in ME (10-30 keV) and HE (20-250 keV),
while the second major bump are very bright in all three telescopes
(HE, ME and LE), which was also detected by INTEGRAL (Atel #13685) and
Konus-Wind (GCN #27669
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 , Atel #13688).
In addition, there is a minor soft bump in LE at the early phase of
this flare which is marginally seen in ME data and absent in HE data.

In HE and ME, there are two narrow peaks (14:34:24.4175 UT and
14:34:24.4475 UT) riding on the second major bump.
In LE, these two narrow peaks are also visible, although the first peak
is rather weak. Considering that the separation time between these two
narrow peaks (~30 ms) is almost the same as that of the radio ones
(~30 ms, Atel #13681), and that the apparent time lag between these two
peaks and radio peaks (~8.6 s) is in perfect agreement with
the calculated dispersion (8.63 s) between X-ray and radio
using the measured DM (332.81 pc/cc) by CHIME/FRB (Atel #13681),
we suggest that these two peaks are very likely the X-ray
and hard X-ray counterparts of the double-peaked radio burst
reported by CHIME/FRB (Atel #13681).

C. K. Li, Y. L. Tuo, M. Y. Ge, X. B. Li, J. Y. Liao, C. Cai,
S. L. Xiong, C. Z. Liu, Y. Chen, X. L. Cao (IHEP), T. P. Li (IHEP/THU),
S. M. Jia, J. Y. Nie, F. J. Lu, L. M. Song, M. Wu, Y. P. Xu,
S. N. Zhang (IHEP), L. Lin (BNU), B. Zhang (UNLV),
report on behalf of the Insight-HXMT team:

Around the trigger time (T0=2020-04-30T21:43:00.5 UTC) of the highly
polarised radio burst event reported by FAST (ATel #13699),
Insight-HXMT was carrying out the ToO observation
of SGR 1935+2154 without any occultation by the Earth.

Within T0 +/- 50 s, no significant excess events (SNR > 3 sigma)
are found in a search of the Insight-HXMT LE (1-10 keV), ME(10-30 keV)
and HE (27-250 keV) light curves.

Assuming the same spectral
model to the X-ray counterpart that we reported in ATel #13687,
and with one second timescale (1 s) coming from the position
of SGR1935+2154, the 3-sigma fluence upper-limits are as following:

Model: wabs*Cutoffpl (nH=2.6,PhoIndex=1.44, Ecut=69.8 keV):
LE:�� 2.68e-09 erg cm^-2
ME:�� 3.45e-09 erg cm^-2
HE:�� 4.46e-09 erg cm^-2

Insight-HXMT will continue to observe SGR 1935+2154 with LE, ME and HE
until 2020-05-06 01:20:47 UT.

Insight-HXMT is the first Chinese space X-ray telescope, which was
funded jointly by the China National Space Administration (CNSA) and
the Chinese Academy of Sciences (CAS).
More information could be found at: http://www.hxmt.org.

Zhang S.-N., Li C.-K., Zheng S.-J., Li X.-B., Tuo Y.-L., Ge M.-Y., Xiao S.,
Xiong S.-L., Zhao X.-F., Tan Y., Cai C., Jia S.-M., Nie J.-Y., Zhao H.-S.,
Luo Q., Li B., Lu F. J., Song L.-M., Liu C.-Z., Chen Y., Cao X.-L.,
Xu Y.-P., Li T.-P. (IHEP), Lin L. (BNU), Zhang B. (UNLV),
on behalf of the Insight-HXMT team:

In the Insight-HXMT light curves of SGR 1935+2154 we reported
in Atel #13687 & #13696 and GCN #27675
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 , the reference time (denoted as T0)
of the burst is 14:34:24.5000 UT of April 28. Here we clarify that it is
the arrival time at the Insight-HXMT satellite. Considering the position
of the satellite in the geocentric coordinate system, the arrival time at
the satellite is 11.443 ms earlier than the geocentric time, which means
that T0 at the geocenter is 14:34:24.5114 UT of April 28, 2020.

�A. Ursi (INAF/IAPS), F. Verrecchia (SSDC, and INAF/OAR), M. Tavani
(INAF/IAPS, and Univ. Roma Tor Vergata), C. Casentini (INAF/IAPS), M.
Pilia (INAF/OA-Cagliari), C. Pittori (SSDC, and INAF/OAR),� A. Argan, M.
Cardillo, Y. Evangelista, G. Piano (INAF/IAPS), F. Lucarelli (SSDC, and
INAF/OAR), A. Bulgarelli, V. Fioretti, F. Fuschino, N. Parmiggiani
(INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University),
A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ. Trieste
and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of the
AGILE Team:

The AGILE satellite detected a short hard X-ray burst at T0 = 2020-05-03
23:25:13.50 (UT).

The event is visible in the scientific ratemeters of the SuperAGILE (SA;
20-60 keV) detector and of the Anti-Coincidence (AC, 50-200 keV). The event
lasted ~0.5 s and released a total number of ~360 counts in the SA 
ratemeters
(above a background of ~60 Hz) while ~800 counts in the AC ratemeters 
(above
a background of ~4200 Hz). The SA and AC ratemeters light curves can be 
found at

http://www.agilescienceapp.it/notices/AGILE_RM_SGR1935+2154_20200503.png .

Considering the geometry of the satellite at T0, the burst detection is
compatible with a source at the position of SGR 1935+2154.

Additional analysis of AGILE data is in progress.

Li X.-B., Li C.-K., Xue W.-C., Ge M.-Y., Xiong S.-L.,
Jia S.-M., Nie J.-Y., Zhao H.-S., Li B.,
Lu F.-J., Song L.-M., Liu C.-Z., Chen Y., Cao X.-L., Xu Y.-P.,
Li T.-P.,�� Zhang S.-N.(IHEP), Lin L. (BNU), Zhang B. (UNLV),
on behalf of the Insight-HXMT team:

During the ToO observation to SGR 1935+2154, Insight-HXMT/HE detected
a short (~0.2 s) and bright burst at 2020-05-03 23:25:13.4 UT
(satellite time), which was also detected by Fermi/GBM (trigNum 610241118)
and AGILE (GCN #27687
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 ). According to the relative rates in 17 detectors
of HE (20-250 keV), this burst is consistent as from SGR 1935+2154.

The HE light curve consists of two major bumps with a
separation time of ~50 ms, and a relatively weaker but narrower peak,
which is similar to the FRB-associated burst at 14:34:24.5 UT of April 28
(GCN 27675
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 , Atel #13687, Atel #13696) but with a much higher peak flux.

The HE light curves have been corrected for data saturation
caused by the extreme brightness of this burst in HE.
HE detectors are divided into 3 groups, i.e. PDAU 0, PDAU 1 and PDAU 2.
Each group consists of 6 detectors and has implemented data saturation
correction separately. The Insight-HXMT/HE light curve could be found at:
http://newshxmt.ihep.ac.cn/images/grb/SGR1935_20200503T23.png

After receiving the ME (5-30 keV) and LE (1-10 keV) data, more analysis
results will be reported.

Alexis Coleiro (APC/Universite de Paris) and Damien Dornic (CPPM/CNRS) on behalf of the ANTARES Collaboration. 

Following the detection of fast radio bursts (ATel #13681 <http://www.astronomerstelegram.org/?read=13681>, #13682 <http://www.astronomerstelegram.org/?read=13682>,  #13684 <http://www.astronomerstelegram.org/?read=13684>) accompanied with X-ray flares (GCN Circular #27657
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  <http://gcn.gsfc.nasa.gov/gcn/gcn3/27657.gcn3
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 >, #27659 <http://gcn.gsfc.nasa.gov/gcn/gcn3/27659.gcn3
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 >, #27661 <http://gcn.gsfc.nasa.gov/gcn/gcn3/27661.gcn3
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 >; ATel #13675 <http://www.astronomerstelegram.org/?read=13675>, #13678 <http://www.astronomerstelegram.org/?read=13678>, #13679 <http://www.astronomerstelegram.org/?read=13679>,  #13685 <http://www.astronomerstelegram.org/?read=13685>, #13686 <http://www.astronomerstelegram.org/?read=13686>, #13687 <http://www.astronomerstelegram.org/?read=13687>, #13688 <http://www.astronomerstelegram.org/?read=13688>), we have performed a search, using ANTARES data, for up-going muon neutrino candidates from the direction of  SGR 1935+2154 in a time window of +/- 1h around the time of the X-ray trigger (14:34:24 UTC). At this time, the source was located 19 degrees below the horizon for ANTARES, and remained visible over the whole  +/- 1h time window.  

No up-going muon neutrino candidate events were recorded at the location of the source.
This leads to a preliminary 90% confidence level upper limit on the muon-neutrino fluence from a point source of 14 GeV.cm^-2 over the energy range 5.6 TeV ��� 5.4 PeV (the range corresponding to 5-95% of the detectable flux) for an E^-2 power-law spectrum, and 30 GeV.cm^-2 (1 TeV - 515 TeV) for an E^-2.5 spectrum.

A search over an extended time window of +/- 1 day has also yielded no detection (38% visibility).

ANTARES <http://antares.in2p3.fr/> is the largest undersea neutrino detector (Mediterranean Sea) and it is primarily sensitive to astrophysical neutrinos in the TeV-PeV energy range. At 10 TeV, the median angular resolution for muon neutrinos is about 0.5 degrees. In the range 1-100 TeV ANTARES has a competitive sensitivity to this position in the sky.

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. V. Golovin, A. S. Kozyrev, M. L. Litvak,
and A. B. Sanin, on behalf of the HEND-Odyssey GRB team,

A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

S. Barthelmy, J. Cummings, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team, and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

A bright, short-duration, soft burst
was detected by Konus-Wind, INTEGRAL (SPI-ACS),
Mars-Odyssey (HEND), CALET(GBM), and Swift (BAT)
at about 22323 s UT (06:12:03) on May 10.
The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
 ---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
  293.680 (19h 34m 43s) +21.858 (+21d 51' 27")
 Corners:
  294.067 (19h 36m 16s) +22.043 (+22d 02' 34")
  293.954 (19h 35m 49s) +22.349 (+22d 20' 58")
  293.295 (19h 33m 11s) +21.669 (+21d 40' 09")
  293.409 (19h 33m 38s) +21.360 (+21d 21' 36")
 ---------------------------------------------
The error box area is 937 sq. arcmin, and its maximum
dimension is 1.1 deg (the minimum one is 17 arcmin).
The Sun distance was 104 deg.

This box may be improved.

The position of SGR 1935+2154 is inside the box
at 3.7 arcmin from its center.

Given the positional coincidence of this burst with
SGR 1935+2154, its time history, and softness of its
spectrum (as observed by Konus-Wind), we conclude that
this burst likely originated from SGR 1935+2154.

A triangulation map is posted at
http://www.ioffe.ru/LEA/SGRs/200510_T22322/IPN/

The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.

A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

Two bright, short bursts from SGR 1935+2154
(IPN triangulation: Hurley et al., GCN Circ. 27714
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 )
triggered Konus-Wind at 22322.624 s UT (06:12:02.624)
and 78677.28 s UT (21:51:17.280) on 2020 May 10.

The first burst light curve shows a single, very bright pulse
started with a sharp rise and then smoothly decayed
to the background level. The second burst light curve shows two
pulses separated by a ~0.15 s gap.
Both bursts have a total duration of ~0.4 s.
The emission is seen up to ~500 keV.

As measured by KW, the burst fluences and peak fluxes are as follows:
------------------------------------------------------------------
#  Date       T0(KW) s UT                   Fl*           PF**
------------------------------------------------------------------
1 20200510 22322.624 s UT(06:12:02.624)  8.70 +/-0.22  38.9 +/-2.0
2 20200510 78677.280 s UT(21:51:17.280)  2.44 +/-0.10  17.8 +/-1.5
------------------------------------------------------------------
*  -  Fluence (20-200 keV) in units of 1e-6 erg/cm2

** - Peak Flux (20-200 keV) on 16-ms time scale
        in units of 1e-6 erg/cm2/s

The time-averaged spectra of the bursts are well fit
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with the following parameters:
-------------------------------------------------------------
#   Tbeg-Tend         alpha            Ep(keV)    chi2/dof
-------------------------------------------------------------
1   0 - 0.256    0.08(-0.23,+0.24)    47(-2,+2)     56/25
2   0 - 0.256    0.49(-0.65,+0.71)    37(-3,+2)     39/24
-------------------------------------------------------------

The Konus-Wind light curves of the bursts are available at
http://www.ioffe.ru/LEA/SGRs/200510_T22322/
http://www.ioffe.ru/LEA/SGRs/200510_T78677/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a SGR 1935+2154, which was also detected by IPN (Hurley K. et al.,GCN #27714), Konus Wind (Ridnaia A. et al.,GCN #27715) and Insight-HXMT (Zhang S. et al., GCN #27718
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 ).

The source was clearly detected in the 40-200 keV energy range. The light curve showed a single peak of emission peaking at 2020-05-10 06:12:00.750 UT. The measured peak count rate associated with the burst is 3283 +/- 61 cts/s above the background in the combined data of four quadrants, with a total of 1770 +/- 3 cts. The local mean background count rate was 566 +/- 1.0 cts/s. Using cumulative rates, we measure a T90 of 0.243 +/- 0.0004 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

The other burst detected by Konus Wind (UT: 21:51:17.280), wasn't detected due to Earth Occultation.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.

F. Verrecchia (SSDC, and INAF/OAR), A. Ursi (INAF/IAPS), M. Tavani
(INAF/IAPS, and Univ. Roma Tor Vergata), C. Casentini (INAF/IAPS), M.
Pilia (INAF/OA-Cagliari), C. Pittori (SSDC, and INAF/OAR),�� A. Argan, M.
Cardillo, Y. Evangelista, G. Piano (INAF/IAPS), F. Lucarelli (SSDC, and
INAF/OAR), A. Bulgarelli, V. Fioretti, F. Fuschino, N. Parmiggiani
(INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University),
A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ. Trieste
and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of the
AGILE Team:

The AGILE satellite detected a short hard X-ray burst at T0 = 2020-05-10
06:12:03.5 (UT). For technical reasons data were processed with a delay
of more than a day.

The event is visible in the scientific ratemeters of the SuperAGILE (SA;
20-60 keV) detector and of the Anti-Coincidence (AC, 50-200 keV). The
event lasted ~0.5 s and released a total number of ~100 counts in the SA
ratemeter (above a background of ~43 Hz), and ~937 counts in the AC
ratemeter (above a background of ~4700 Hz). The light curves of SA and
AC ratemeters can be found at
https://tools.ssdc.asi.it/ImgView/Agile/SGR1935burst_lc_2020-05-1027
.

Considering the geometry of the satellite at T0, the burst detection is
compatible with a source at the position of SGR 1935+2154 as determined in
GCN #27714
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  (Hurley et al.).

Additional analysis of AGILE data is in progress.

Y. Huang, S. J. Zheng, F. J. Lu, S. N. Zhang, L. M. Song, W. X. Peng,
S. L. Xiong, S. Xiao, C. Cai, X. Y. Zhao, X. Ma, P. Zhang, B. X. Zhang,
Z. H. An, C. Chen, G. Chen, W. Chen, M. Gao, K. Gong, D. Y. Guo,
J. J. He, B. Li, C. Li, C. Y. Li, J. H. Li, Q. X. Li,
X. B. Li, X. Q. Li, Y. G. Li, X. H. Liang, J. Y. Liao, J. C. Liu,
X. J. Liu, Y. Q. Liu, Q. Luo, G. Ou, W. X. Peng, R. Qiao,
D. L. Shi, J. Y. Shi, X. Y. Song, G. X. Sun, X. L. Sun,
Y. L. Tuo, C. W. Wang, J. Z. Wang, P. Wang, X. Y. Wen, Y. B. Xu,
Y. P. Xu, W. C. Xue, S. Yang, M. Yao, Q. B. Yi, C. Y. Zhang,
D. L. Zhang, Fan Zhang, Fei Zhang, H. M. Zhang, K. Zhang,
S. N. Zhang, Y. Q. Zhang, Z. Zhang, S. Y. Zhao, Y. Zhao, C. Zheng,
X. Zhou (IHEP),
report on behalf of GECAM team:

During the commissioning phase, GECAM-B was triggered in-flight by
a short burst (trig# 65429420) at 2021-01-27T06:50:20.750 UTC (T0).
Its alert data was promptly downlinked to the ground through the
short message service of BeiDou Navigation Satellite System (BDS).
The time latency of the first BeiDou message relative to the trigger time
is about 1 minute.

According to the BDS alert data, this burst mainly consists of
two pulses with a duration of roughly 100 ms.
There is no much emission above 100 keV.

The in-flight position (J2000) given by GECAM-B is:
Ra: 291.31 deg Dec: 23.67 deg
Galactic lon: 57.74 deg, lat: 3.63 deg
Err: 2.16 deg (1-sigma, statistical only)
The current systematic error of location is estimated to be several degrees
which could be minimized by the ongoing calibration.

The GECAM light curve could be found here:
http://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_hrlc_grd_65429420.png

The GECAM preliminary location could be found here:
http://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_skymap_65429420.png

According to the location and light curve, we suggest that this burst
is very likely from SGR 1935+2154 which seems to be active recently.

This is the first short trigger of GECAM which downlinked the
high resolution light curve through BDS successfully.

As the detailed science data are downloaded, all analyses would be improved.

Please note that all GECAM results here are preliminary. The final analysis
will be published in journal papers or GECAM online catalog.

Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor
(GECAM) mission consists of two small satellites (GECAM-A and GECAM-B) in
Low Earth Orbit (600 km, 29 deg), launched on Dec 10, 2020 (Beijing Time),
which was funded by the Chinese Academy of Sciences (CAS).

A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

and

S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team, report:

The bright, short-duration, soft burst
(GECAM detection: Huang et al., GCN Circ. 29363
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 )
was detected by GECAM, Konus-Wind, and Swift (BAT)
at about 24617 s UT (06:50:17) on January 27.
The burst was outside the coded field of view of the BAT.

We have triangulated it to a Konus-BAT annulus centered at
RA(2000)=315.213 deg (21h 00m 51s)  Dec(2000)=-14.116 deg (-14d 06' 56"),
whose radius is 41.658 +/- 0.174 deg (3 sigma).

The position of SGR 1935+2154 lies inside the annulus at 3.5 arcmin
from its center line.

Given the positional coincidence (initially suggested in GCN 29363
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 ) of
this burst with SGR 1935+2154, its time history, and softness of its
spectrum (as observed by Konus-Wind), we conclude this burst is
likely originated from SGR 1935+2154.

A triangulation map is posted at
http://www.ioffe.ru/LEA/SGRs/210127_T24616/IPN/

The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.

A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

Two bright, short bursts from SGR 1935+2154
(GECAM detection: Huang et al., GCN Circ. 29363
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IPN triangulation: Ridnaia et al., GCN Circ. 29365
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 )
triggered Konus-Wind on 2021 January 27 at
24616.685 s UT (06:50:16.685), hereafter burst #1; and
on 2021 January 29 at 25196.932 s UT (06:59:56.932), burst #2.

The burst light curves feature a sharp rise,
followed by a gradual decay, and, finally,
a quick return of a count rate to the background level.
Additionally, the main pulse of burst #1 is preceded by
a weaker, partially overlapped sub-pulse.
The burst total durations are  ~100 ms (#1) and ~200 ms (#2).
The emission in both bursts is seen up to ~200 keV.

As measured by KW, the burst fluences and peak fluxes are as follows:
------------------------------------------------------------------
#  Date       T0(KW) s UT                   Fl*           PF**
------------------------------------------------------------------
1 20210127 24616.685 s UT(06:50:16.685)  0.91 +/-0.07  16.0 +/-3.2
2 20210129 25196.932 s UT(06:59:56.932)  3.14 +/-0.11  27.5 +/-4.4
------------------------------------------------------------------
*  -  Fluence (20-500 keV) in units of 1e-6 erg/cm2

** - Peak Flux (20-500 keV) on 2-ms time scale
        in units of 1e-6 erg/cm2/s

Time-averaged spectra of the bursts are well fit
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with the following parameters:
-------------------------------------------------------------
#   Tbeg-Tend         alpha            Ep(keV)    chi2/dof
-------------------------------------------------------------
1   0 - 0.064    -0.21(-1.00,+1.20)    31(-10,+5)   13/11
2   0 - 0.192    -0.33(-0.37,+0.40)    34(-3,+3)     14/20
-------------------------------------------------------------

These spectral parameters are typical of a few dosen SGR 1935+2154
short bursts detected by KW previously (with the notable exception
of the April 28 SGR/FRB event).

The Konus-Wind light curves of the bursts are available at
http://www.ioffe.ru/LEA/SGRs/210127_T24616/
http://www.ioffe.ru/LEA/SGRs/210129_T25196/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

P. Wang, C. Cai, X. Y. Zhao, X. B. Li, W. X. Peng, L. M. Song, S. L. Xiong,
M. Y. Ge, S. J. Zheng, Y. Huang, X. Ma, S. Xiao, P. Zhang, B. X. Zhang,
Z. H. An, C. Chen, G. Chen, W. Chen, M. Gao, K. Gong, D. Y. Guo,
J. J. He, B. Li, C. Li, C. Y. Li, J. H. Li, Q. X. Li,
X. Q. Li, Y. G. Li, X. H. Liang, J. Y. Liao, J. C. Liu,
X. J. Liu, Y. Q. Liu, F. J. Lu, Q. Luo, G. Ou, R. Qiao,
D. L. Shi, J. Y. Shi, X. Y. Song, G. X. Sun, X. L. Sun,
Y. L. Tuo, C. W. Wang, J. Z. Wang, P. Wang, X. Y. Wen, Y. B. Xu,
Y. P. Xu, W. C. Xue, S. Yang, M. Yao, Q. B. Yi, C. Y. Zhang,
D. L. Zhang, Fan Zhang, Fei Zhang, H. M. Zhang, K. Zhang, S. N. Zhang,
Y. Q. Zhang, Z. Zhang, S. Y. Zhao, Y. Zhao, C. Zheng, X. Zhou (IHEP),
report on behalf of GECAM team:

Since the first report of a bright burst from SGR 1935+2154 (Y. Huang et 
al.,
GCN 29363
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 ), GECAM has detected a series of bursts probably from this source,
either from in-flight trigger or from ground search of the data.
Here is the list of these bursts:

TrigTime(UTC)
2021-01-27T06:50:20.750
2021-01-29T14:17:25.000
2021-01-29T17:51:00.850
2021-01-30T08:39:53.850
2021-01-30T09:46:01.050
2021-01-30T17:40:54.800

Locations of all these bursts are consistent with SGR 1935+2154.

Please note that all GECAM results here are preliminary. The final analysis
will be published in journal papers or GECAM online catalog.

Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor
(GECAM) mission consists of two small satellites (GECAM-A and GECAM-B) in
Low Earth Orbit (600 km, 29 deg), launched on Dec 10, 2020 (Beijing Time),
which was funded by the Chinese Academy of Sciences (CAS).

S.Mereghetti (INAF, IASF-Milano), V.Savchenko, C.Ferrigno, E.Bozzo (ISDC,
Versoix), D.Gotz (CEA, Saclay), L.Ducci (IAAT, Germany and ISDC, Versoix)
and J.Borkowski (CAMK, Torun) report:

A burst from SGR 1935+2154,  that is currently in an active state (e.g. GCN
29365
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 , 29373
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 , 29374
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 , 29377
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 ), has been detected by IBAS in the IBIS/ISGRI
data at 12:54:26.71 UT of February 2, 2021.

The burst had a single peak lasting about 50 ms and  a fluence of  1.14e-7
+/- 0.14e-7  erg/cm^2 in the 30-100 keV energy range.

The off-line analysis confirmed the  coordinates derived by IBAS and
distributed in real time in the alert packet (n. 8965) that associated this
event with SGR 1935+2154

S. Ricciarini (U of Florence),
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC),
M. L. Cherry (LSU), P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

During the recent reactivation of SGR 1935+2154 reported by
GECAM (Huang et al., GCN Circ. 29363
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 ; Wang et al. GCN Circ. 29377
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 ),
IPN (Ridania et al., GCN Circ. 29365
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 ), Konus-Wind (Ridnaia et al.,
GCN Circ. 29373
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 ), Fermi-GBM (Roberts et al., GCN Circ. 29374
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 , ATel #14359),
and INTEGRAL-IBAS (Mereghetti et al., GCN Circ. 29381
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 )
the CALET Gamma-ray Burst Monitor (CGBM) has triggered on three bright
short soft bursts from this SGR (alerted triggers 1295912101, 1295951738,
and 1296063650).
Additional five weaker short soft bursts observed in the waiting mode
(125-ms time resolution, 8 energy channels) with high S/N were also likely
originated from SGR 1935+2154.

The following table summarizes the bursts:

       Time, UTC           Mode     Other reported detections
-------------------------------------------------------------
2021-01-28 23:35:02.450   Trig         Fermi-GBM
2021-01-29 02:46:23       BG           Fermi-GBM
2021-01-29 10:35:39.707   Trig         Fermi-GBM
2021-01-29 15:23:30       BG           -
2021-01-29 21:15:56       BG           Fermi-GBM
2021-01-30 13:05:39       BG           -
2021-01-30 17:40:54.610   Trig         GECAM
2021-01-31 03:01:28       BG           -
--------------------------------------------------------------

At the listed times, SGR 1935+2154 was in the FOVs of the CGBM detectors.

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at the Waseda University.

T. Kawamuro (UDP/NAOJ), M. Serino (AGU),
H. Negoro, M. Nakajima, M. Aoki, K. Kobayashi, R. Takagi, K. Asakura, K. Seino (Nihon U.),
T. Mihara, T. Tamagawa, M. Matsuoka (RIKEN),
T. Sakamoto, S. Sugita, H. Nishida, K. Komachi, A. Yoshida (AGU),
Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, Y. Okamoto, S. Kitakoga (Chuo U.),
M. Shidatsu (Ehime U.),
N. Kawai, R. Adachi, M. Niwano, R. Hosokawa (Tokyo Tech),
S. Nakahira, Y. Sugawara, S. Ueno, H. Tomida, M. Ishikawa, M. Tominaga, T. Nagatsuka (JAXA),
Y. Ueda, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake, Y. Goto, R. Uematsu (Kyoto U.),
H. Tsunemi (Osaka U.),
M. Yamauchi, K. Kurogi, K. Miike (Miyazaki U.),
K. Yamaoka (Nagoya U.),
Y. Kawakubo (LSU),
M. Sugizaki (NAOC) 
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered on one short burst 
at 00:35:52 UTC on 2021/02/07 from a position consistent with an active Soft 
Gamma Repeater of SGR 1935+2154 (GCN 29363
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 , 29365
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 , 29373
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 , 
29374
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 , 29377
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 , 29381
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 , 29383
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 , 29388
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 , Atel #14359).

The duration of the burst is about 0.1 sec, and its 5 ms peak flux reached about 
130 Crab in the 2-20 keV band.

S. Lesage (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 02:34:10.19 UT on 24 June 2021, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located a bright, SGR-like burst from the direction of
the magnetar SGR 1935+2154 (trigger 646194855/210624107).

The on-ground calculated location, using the Fermi GBM trigger data, is
RA = 293.73, Dec = 21.90 (J2000 degrees), with a statistical uncertainty
of 2.72 degrees and is consistent with the known position of the SGR.

The angle from the Fermi LAT boresight at the GBM trigger time is 37 degrees.

The burst has a duration (T90) of about 0.08 s (10-300 keV).

It is best fit by a double-blackbody model with temperatures of
kT1 = 7.4 +/- 0.7 keV and kT2 = 13.3 +/- 1.5 keV.

The event fluence (10-300 keV) from T0-0.016s to T0+0.064s is
(1.16 +/- 0.03)E-06 erg/cm^2. The average photon flux in the
10-300 keV band during this period is 194 +/- 4 ph/s/cm^2.

The spectral analysis results presented above are preliminary.

For Fermi GBM data and info, please visit the official Fermi GBM
Support Page:https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"

S.Mereghetti (INAF, IASF-Milano) on behalf of the IBAS localization team
reports:

A  short burst has been detected by IBAS in the  IBIS/ISGRI data at
17:14:50.7  UT of 2021 July 6. The burst was clearly localized at the
position of the galactic magnetar SGR 1935+2154 and a notice with the
source identification was distributed in real time (IBAS Alert Packet
n.9294).

The burst had a duration of about 50 ms.  A preliminary analysis indicates
a fluence of  about 1e-7  erg/cmq (20-200 keV).

S. Xiao, Y. Huang, X. Y. Zhao, S. L. Xiong, W. C. Xue, X. Y. Song, C. Cai,
S. L. Xie, J. C. Liu, C. Y. Li, Y. Q. Zhang,  Y. Zhao, Z. W. Guo, C. Zheng,
Z. H. An, C. Chen, G. Chen, W. Chen, M. Gao, K. Gong, D. Y. Guo, J. J. He,
B. Li, C. Li, J. H. Li, Q. X. Li, X. B. Li, X. Q. Li, Y. G. Li, X. H. Liang,
J. Y. Liao, J. C. Liu, X. J. Liu, Y. Q. Liu, F. J. Lu, Q. Luo, X. Ma,
G. Ou, W. X. Peng, R. Qiao, D. L. Shi, J. Y. Shi, L. M. Song,
G. X. Sun, X. L. Sun, Y. L. Tuo, C. W. Wang, J. Z. Wang,
P. Wang, X. Y. Wen, Y. B. Xu, Y. P. Xu, S. Yang, M. Yao, Q. B. Yi,
B. X. Zhang, C. Y. Zhang, D. L. Zhang, Fan Zhang, Fei Zhang, H. M. Zhang,
K. Zhang, P. Zhang, S. N. Zhang, Z. Zhang, S. Y. Zhao, S. J. Zheng,
X. Zhou (IHEP), report on behalf of GECAM team:

During the commissioning phase, GECAM-B was triggered in-flight by
a bright short burst (trig# 79317211) at 2021-07-07T00:33:31.700 UTC (T0),
which was also observed by Fermi/GBM (trig# bn210707023).
Its alert data was promptly downlinked to the ground through the
short message service of BeiDou Navigation Satellite System (BDS).
The time latency of the first BeiDou message relative to the trigger time
is about 1 minute.

According to the BDS alert data, this burst mainly consists of
two overlapping pulses with a duration of about 100 ms.
Using the light curves and spectrum in the BDS alert data, 
GECAM-B localized this burst to the following position (J2000): 
Ra: 291.99 deg 
Dec: 24.30 deg
Err: 3.07 deg (1-sigma, statistical only)
The current systematic error of location is estimated to be several degrees.

This location is consistent with SGR J1935+2154 within the error.

The GECAM light curve could be found here:
http://twiki.ihep.ac.cn/pub/GECAM/GRBList/79317211_lc.png

The GECAM preliminary location could be found here:
http://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_skymap_bdm_79317211_V01.png

Please note that all GECAM results here are preliminary. The final analysis
will be published in journal papers or GECAM online catalog.

Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor
(GECAM) mission consists of two small satellites (GECAM-A and GECAM-B) in
Low Earth Orbit (600 km, 29 deg), launched on Dec 10, 2020 (Beijing Time),
which was funded by the Chinese Academy of Sciences (CAS).

D. M. Palmer (LANL) on behalf of the Swift team reports:

A short burst has been detected by the BAT instrument at 23:59:32.6 on 2021-07-04 UT from SGR 1935+2154.  The burst had a duration of about 150 ms with a peak count rate of 2,000 counts/second (15-350 keV on the 64 ms timescale).

The burst reported from the same source by INTEGRAL at 17:14:50.7 of 2021-07-06 UT (GCN #30395
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  Mereghetti et al.) is also detected as a count rate increase in BAT of 65,000 counts/s on the 64 ms timescale.  However, Swift was slewing at that time and so BAT could not localize the source.

A. Ridnaia, D. Frederiks, S. Golenetskii, A. Lysenko,
D. Svinkin, A. Tsvetkova,  M. Ulanov, and T. Cline
on behalf of the Konus-Wind team, report:

The short burst from SGR 1935+2154
(INTEGRAL detection: Mereghetti, GCN 30395
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 )
triggered Konus-Wind on 2021 July 6 at
T0=62093.331 s UT (17:14:53.331).

The burst light curve features a sharp rise,
followed by a gradual decay, and, finally,
a quick return of a count rate to the background level.
The burst total duration is ~50 ms.
The emission is seen up to ~200 keV.

The Konus-Wind light curve of this burst is available at
http://www.ioffe.ru/LEA/SGRs/210706_T62093/

As observed by Konus-Wind, the burst
had a fluence of 8.90(-0.22,+1.45)x10^-7 erg/cm2,
and a 2-ms peak flux, measured from T0-0.004 s,
of 2.56(-0.43,+0.60)x10^-5 erg/cm2/s
(both in the 20 - 500 keV energy range).

Since the brightest part of the burst emission was detected
before the trigger, the spectral analysis was performed using
the KW 3-channel light curve data.

Modelling the time-integrated spectrum of the burst
(measured from T0-0.038 to T0+0.018 s)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep),
yields alpha = -1.15(-0.72,+2.34) and Ep = 23(-17,+16) keV.

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.

C. Cai, S. L. Xiong, S. Xiao, Y. Huang, X. Y. Zhao, W. C. Xue, X. Y. Song, 
S. L. Xie, J. C. Liu, C. Y. Li, Y. Q. Zhang,  Y. Zhao, Z. W. Guo, C. Zheng,
Z. H. An, C. Chen, G. Chen, W. Chen, M. Gao, K. Gong, D. Y. Guo, J. J. He,
B. Li, C. Li, J. H. Li, Q. X. Li, X. B. Li, X. Q. Li, Y. G. Li, X. H. Liang,
J. Y. Liao, J. C. Liu, X. J. Liu, Y. Q. Liu, F. J. Lu, Q. Luo, X. Ma,
G. Ou, W. X. Peng, R. Qiao, D. L. Shi, J. Y. Shi, L. M. Song,
G. X. Sun, X. L. Sun, Y. L. Tuo, C. W. Wang, J. Z. Wang,
P. Wang, X. Y. Wen, Y. B. Xu, Y. P. Xu, S. Yang, M. Yao, Q. B. Yi,
B. X. Zhang, C. Y. Zhang, D. L. Zhang, Fan Zhang, Fei Zhang, H. M. Zhang,
K. Zhang, P. Zhang, S. N. Zhang, Z. Zhang, S. Y. Zhao, S. J. Zheng,
X. Zhou (IHEP), report on behalf of GECAM team:

During the commissioning phase, GECAM-B was triggered in-flight by
a short burst (trig# 79402698) at 2021-07-08T00:18:18.850 UTC (T0).
Its alert data was promptly downlinked to the ground through the
short message service of BeiDou Navigation Satellite System (BDS).
The time latency of the first BeiDou message relative to the trigger time
is about 1 minute.

According to the BDS alert data, this burst mainly consists of
a single pulse with a duration of about 100 ms.
The location is consistent with SGR J1935+2154 within the error.

The GECAM light curve could be found here:
http://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_lc_grd_all_combine_79402698.png

As the detailed science data are downloaded, all analyses would be improved.

Please note that all GECAM results here are preliminary. The final analysis
will be published in journal papers or GECAM online catalog.

Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor
(GECAM) mission consists of two small satellites (GECAM-A and GECAM-B) in
Low Earth Orbit (600 km, 29 deg), launched on Dec 10, 2020 (Beijing Time),
which was funded by the Chinese Academy of Sciences (CAS).

A. Ridnaia, D. Frederiks, S. Golenetskii, A. Lysenko,
D. Svinkin, A. Tsvetkova,  M. Ulanov, and T. Cline
on behalf of the Konus-Wind team, report:

The short burst from SGR 1935+2154
(GECAM detection: Xiao et al., GCN 30400
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 ;
Fermi GBM Observations: Hamburg et al., GCN 30407
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 )
triggered Konus-Wind on 2021 July 7 at
T0=2015.644 s UT (00:33:35.644).

The burst light curve shows a single pulse with a total
duration of ~120 ms. The emission is seen up to ~200 keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/SGRs/210707_T02015/

As observed by Konus-Wind, the burst
had a fluence of 1.48(-0.08,+0.08)x10^-6 erg/cm2,
and a 2-ms peak flux, measured from T0-0.014 s,
of 1.94(-0.39,+0.39)x10^-5 erg/cm2/s
(both in the 20 - 500 keV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+0.064 s)
is best fit in the 20 - 200 keV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = 0.43(-0.80,+0.88)
and Ep = 38(-4,+3) keV (chi2 = 12/14 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

C. Cai, S. L. Xiong, S. Xiao, Y. Huang, X. Y. Zhao, W. C. Xue, X. Y. Song, 
S. L. Xie, J. C. Liu, C. Y. Li, Y. Q. Zhang,  Y. Zhao, Z. W. Guo, C. Zheng,
Z. H. An, C. Chen, G. Chen, W. Chen, M. Gao, K. Gong, D. Y. Guo, J. J. He,
B. Li, C. Li, J. H. Li, Q. X. Li, X. B. Li, X. Q. Li, Y. G. Li, X. H. Liang,
J. Y. Liao, J. C. Liu, X. J. Liu, Y. Q. Liu, F. J. Lu, Q. Luo, X. Ma,
G. Ou, W. X. Peng, R. Qiao, D. L. Shi, J. Y. Shi, L. M. Song,
G. X. Sun, X. L. Sun, Y. L. Tuo, C. W. Wang, J. Z. Wang,
P. Wang, X. Y. Wen, Y. B. Xu, Y. P. Xu, S. Yang, M. Yao, Q. B. Yi,
B. X. Zhang, C. Y. Zhang, D. L. Zhang, Fan Zhang, Fei Zhang, H. M. Zhang,
K. Zhang, P. Zhang, S. N. Zhang, Z. Zhang, S. Y. Zhao, S. J. Zheng,
X. Zhou (IHEP), report on behalf of GECAM team:

During the commissioning phase, GECAM-B was triggered in-flight by
a short burst (trig# 79528675) at 2021-07-09T11:17:55.000 UTC (T0).
Its alert data was promptly downlinked to the ground through the
short message service of BeiDou Navigation Satellite System (BDS).
The time latency of the first BeiDou message relative to the trigger time
is about 1 minute.

According to the BDS alert data, this burst mainly consists of
a single pulse with a duration of about 100 ms. 
Using the light curves and spectrum in the BDS alert data, 
GECAM-B localized this burst to the following position (J2000): 
Ra: 297.00 deg 
Dec: 25.64 deg
Err: 10.87 deg (1-sigma, statistical only)
The current systematic error of location is estimated to be several degrees.

This location is consistent with SGR J1935+2154 within the error.

The GECAM light curve could be found here:
http://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_lc_grd_all_combine_79528675.png

As the detailed science data are downloaded, all analyses would be improved.

Please note that all GECAM results here are preliminary. The final analysis
will be published in journal papers or GECAM online catalog.

Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor
(GECAM) mission consists of two small satellites (GECAM-A and GECAM-B) in
Low Earth Orbit (600 km, 29 deg), launched on Dec 10, 2020 (Beijing Time),
which was funded by the Chinese Academy of Sciences (CAS).

A. Ridnaia, D. Frederiks, S. Golenetskii, A. Lysenko,
D. Svinkin, A. Tsvetkova,  M. Ulanov, and T. Cline
on behalf of the Konus-Wind team, report:

The short, soft burst from SGR 1935+2154
(Fermi GBM trigger 647641569)
triggered Konus-Wind on 2021 July 10 at
T0=73568.532 s UT (20:26:08.532).

The burst light curve shows a single pulse
started at ~T0-150 ms with a total duration of ~200 ms.
The emission is seen up to 200 keV.

The Konus-Wind light curve of this burst is available at
http://www.ioffe.ru/LEA/SGRs/210710_T73568/

As observed by Konus-Wind, the burst
had a fluence of 1.49(-0.17,+0.17)x10^-6 erg/cm2,
and a 2-ms peak flux, measured from T0-0.044 s,
of 1.33(-0.33,+0.33)x10^-5 erg/cm2/s
(both in the 20 - 500 keV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+0.064 s)
is best fit in the 20 - 200 keV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.66(-1.32,+1.91)
and Ep = 25(-22,+9) keV (chi2 = 6/9 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

S. Nakahira (RIKEN),
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), Y. Asaoka (ICRR),
S. Torii, Y. Akaike, K. Kobayashi (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC),
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

During the recent reactivation of SGR 1935+2154 reported by
INTEGRAL (GCN 30395
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 ), GECAM (GCNs 30400
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 , 30415
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 , 30430
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 , 30437
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 , 30449
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 ),
Fermi-GBM (GCN 30407
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 ), and Konus-Wind (GCNs 30409
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 , 30418
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 , 30450
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 )
the CALET Gamma-ray Burst Monitor (CGBM) has triggered on two bright
short soft bursts from this SGR (alerted trigger 1309652996:
http://cgbm.calet.jp/cgbm_trigger/flight/1309652996/
and trigger 1309983742, which was not alerted).
Additional two weaker short soft bursts observed in the waiting mode
(125-ms time resolution, 8 energy channels) with high S/N were also likely
originated from SGR 1935+2154 (these bursts have not been reported by other
instruments so far).

The following table summarizes the bursts:

        Time, UTC           Mode     Other reported detections
--------------------------------------------------------------
2021-07-07 00:33:31.593   Trig      GECAM,Fermi GBM,Konus-Wind
2021-07-10 20:26:04.635   Trig*     Konus-Wind,Fermi GBM
2021-07-11 14:42:55       BG                -
2021-07-12 16:58:51       BG                -
--------------------------------------------------------------
*- Because of a problem in one of the ground alert processing script,
    the GCN notice was not distributed automatically for this trigger.

At the listed times, SGR 1935+2154 was in the FOVs of the CGBM detectors.

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at the Waseda University.

D. Svinkin, S. Golenetskii, D. Frederiks, A. Ridnaia,
A. Lysenko, and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team, and

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
report:

A bright, short-duration, soft burst has been observed by
Konus-Wind, INTEGRAL (SPI-ACS), and Swift (BAT), so far,
at about 536 s UT (00:08:56) on August 5.
The burst was outside the coded field of view of the BAT.

We have triangulated it to a Konus-BAT annulus centered at
RA(2000)=313.877 deg (20h 55m 31s) Dec(2000)=-20.391 deg (-20d 23' 28"),
whose radius is 46.762 +/- 0.249 deg (3 sigma) and
to a Konus-SPI-ACS annulus centered at
RA(2000)=310.504 deg (20h 42m 01s) Dec(2000)=-16.410 deg (-16d 24' 34"),
whose radius is 41.919 +/- 0.512 deg (3 sigma).

This localization may be improved.

The position of SGR 1935+2154 is inside the annuli
at 7.2 arcmin from the center line of the Konus-BAT annulus.

Given the positional coincidence of this burst with SGR 1935+2154, its 
time history, and softness of its spectrum  (as observed by Konus-Wind), 
we conclude this burst is likely originated from SGR 1935+2154.


A triangulation map is posted at
http://www.ioffe.ru/LEA/SGRs/210805_T00539/IPN/

The time history and spectrum will be given in forthcoming GCN Circulars.

A. Ridnaia, D. Frederiks, S. Golenetskii, A. Lysenko,
D. Svinkin, A. Tsvetkova,  M. Ulanov, and T. Cline
on behalf of the Konus-Wind team, report:

The short, soft burst from SGR 1935+2154
(IPN triangulation: Svinkin et al., GCN 30598
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 )
triggered Konus-Wind on 2021 August 5 at
T0=539.958 s UT (00:08:59.958).

The burst light curve shows a single pulse
started at ~T0-70 ms with a total duration of ~165 ms.
The emission is seen up to ~200 keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/SGRs/210805_T00539/

As observed by Konus-Wind, the burst
had a fluence of 1.29(-0.08,+0.08)x10^-6 erg/cm2,
and a 2-ms peak flux, measured from T0-0.014 s,
of 1.62(-0.35,+0.35)x10^-5 erg/cm2/s
(both in the 20 - 500 keV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+0.064 s)
is best fit in the 20 - 200 keV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = 0.39(-0.99,+1.12)
and Ep = 33(-6,+4) keV (chi2 = 11/12 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

I. Chelovekov (IKI), A. Pozanenko (IKI), P. Minaev (IKI), S. Grebenev 
(IKI) report on behalf of the GRB IKI FuN:

Using publicly available data of the INTEGRAL/SPI telescope we localized 
the source of the gamma-ray outburst detected by Konus/WIND (Ridnaia et 
al., GCB 30599), ASC/INTEGRAL and BAT/Swift on August 5, 2021 and 
triangulated by IPN (Svinkin et al., GCB 30598). Duration of the event 
in the SPI above 20 keV is 0.14 s. Its time profile is shown at

http://grb.rssi.ru/SGR1935+2154/SGR1935+2154_SPI_LC_2101-08-05.png

The source was detected at the edge of the SPI FOV (15.07 deg off the 
telescope axis). The map of the sky within the SPI FOV obtained during 
the outburst is given at

http://grb.rssi.ru/SGR1935+2154/SGR1935+2154_SPI_2101-08-05.png

The coordinates of the source, (J2000) R.A.=294.0 deg, Decl.=21.7 deg, 
are determined with an uncertainty of 0.4 deg (radius). The  position of 
the source coincides with that of SGR 1935+2154. Thus we can confirm 
that the outburst on August 5, 00:08:56 (UT) is a part of activity of 
SGR 1935+2154.

A. Ridnaia, S. Golenetskii, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

A. Goldstein, M. S. Briggs, and C. Wilson-Hodge
on behalf of the Fermi-GBM team, and

S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team, report:

A bright, short-duration, soft burst has been observed by
Fermi (GBM), Konus-Wind, and Swift (BAT), so far,
at about 2747 s UT (00:45:47) on September 10.
The burst was outside the coded field of view of the BAT.

We have triangulated it to a Konus-GBM annulus centered at
RA(2000)=326.594 deg (21h 46m 22s)  Dec(2000)=-14.741 deg (-14d 44' 28"),
whose radius is 48.801 +/- 0.199 deg (3 sigma).

This localization may be improved.

The position of SGR 1935+2154 lies inside the annulus at 0.7 arcmin
from its center line.

Given the positional coincidence of this burst with SGR 1935+2154,
its time history, softness of its spectrum (as observed by Konus-Wind),
and reported bursting activity (Xiao et al., GCN Circ. 30797
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 ),
we conclude this burst is likely originated from SGR 1935+2154.

A triangulation map is posted at
http://www.ioffe.ru/LEA/SGRs/210910_T02750/IPN/

The time history and spectrum will be given in forthcoming GCN Circulars.

A. Ridnaia, D. Frederiks, S. Golenetskii, A. Lysenko,
D. Svinkin, A. Tsvetkova,  M. Ulanov, and T. Cline
on behalf of the Konus-Wind team, report:

The very bright burst from SGR 1935+2154
(IPN triangulation: Ridnaia et al., GCN Circ. 30803
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 )
triggered Konus-Wind at T0=2750.499 s UT (00:45:50.499)
on 2021 September 10.

The light curve shows a single pulse with a sharp(<10 ms) rise
and a total duration of ~1.4 s.
The emission is seen up to ~200 keV.

The Konus-Wind light curve of this burst is available at
http://www.ioffe.ru/LEA/SGRs/210910_T02750/

As observed by Konus-Wind, the burst
had a fluence of 2.51(-0.04,+0.04)x10^-5 erg/cm2,
and a 16-ms peak flux, measured from T0+0.322 s,
of 3.09(-0.18,+0.18)x10^-5 erg/cm2/s
(both in the 20 - 500 keV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+0.512 s)
is best fit in the 20 - 200 keV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = 0.21(-0.18,+0.19)
and Ep = 52(-1,+1) keV (chi2 = 37/22 dof).

The rather long duration of the burst along with the
large measured energy fluence put the burst in the class
of "intermediate" SGR bursts. The event is as fluent as
the April 12, 2015 Intermediate Flare
(Kozlova et al. 2016, MNRAS 460, 2008);
the spectrum of the burst is characterized by the
higher peak energy than of the April 12, 2015 IF (Ep~35 keV).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

O.J. Roberts (USRA/NASA-MSFC), J. Wood (USRA/NASA-MSFC),
report on behalf of the Fermi GBM Team:

"At 00:45:46.94 UT on 10 September 2021, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located a bright, SGR-like flare from the direction of
the magnetar SGR 1935+2154 (trigger 652927551/210910032).

The flare was also observed by Konus Wind (Ridnaia et al., GCN 30804
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 ) and
triangulated to an annulus incorporating the SGR position by the IPN (Ridnaia et al., GCN 30803
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 ).
The on-ground calculated location using the Fermi GBM trigger data, is consistent
with the known position of the SGR and the IPN localization.

The angle from the Fermi LAT boresight at the GBM trigger time is 102 degrees.

The burst has a duration (T90) of about 1.4 s (10-1000 keV).

It is best fit by a double-blackbody model with temperatures of
kT1 = 8.51 +/- 0.08 keV and kT2 = 16.55 +/- 0.18 keV.

The event fluence (10-1000 keV) from T0-0.064s to T0+1.328s is
(3.858 +/- 0.011)E-05 erg/cm^2. The average photon flux in the
10-1000 keV band during this period is 522.7 +/- 1.5 ph/s/cm^2.

Fermi GBM has also triggered on 14 other bursts from the direction of SGR 1935+2154 over
the last 4 days, indicating it has entered a stage of heightened activity in this latest outburst:

Date and Time in UTC     Fermi MET (s)
2021-09-06T01:44:30.10  652585475
2021-09-09T18:57:14.86  652906639
2021-09-09T20:21:28.37  652911693
2021-09-10T00:45:46.94  652927551
2021-09-10T01:00:43.71  652928448
2021-09-10T01:13:17.40  652929202
2021-09-10T01:27:05.60  652930030
2021-09-10T02:21:06.44  652933271
2021-09-10T02:36:38.24  652934203
2021-09-10T02:55:10.17  652935315
2021-09-10T05:35:55.51  652944960
2021-09-10T09:12:48.91  652957973
2021-09-10T15:50:56.89  652981861
2021-09-10T23:40:34.46  653010039

The spectral analysis results presented above are preliminary. We encourage multi-wavelength
observations to follow-up this most recent activation. For Fermi GBM data and info, please visit the
 official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"

O.J. Roberts (USRA/NASA-MSFC) reports on behalf of the Fermi GBM Team:

"At 20:16:10.44 UT on 12 September 2021, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located a bright, SGR-like burst from the direction of
the magnetar SGR 1935+2154 (trigger 653170575/210912845).

The GBM on-ground location is consistent with the known position of the SGR.

The angle from the Fermi LAT boresight at the GBM trigger time is 96 degrees.

The event episode has a duration (T90) of about 1 s (10-1000 keV). During this
time interval, there are several very short bursts. The first burst has a
rapid risetime.

The whole event is best fit with a power law function
with an exponential high-energy cutoff. The power law index is 0.08 +/- 0.08 and
the cutoff energy, parameterized as Epeak, is 32.1 +/- 0.3 keV.

The time-integrated event fluence (10-1000 keV) from T0-0.064 to T0+0.944s is
(3.545 +/- 0.038)E-6 erg/cm^2. The average photon flux in the
10-1000 keV band during this period is 84 +/- 1 ph/s/cm^2.

Fermi GBM has also triggered on a further 24 bursts from the direction of SGR 1935+2154
since yesterday's GCN (Roberts and Wood, GCN 30806
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 ):

Date and Time in UTC     Fermi MET (s)
2021-09-12T23:19:32.08  653181577
2021-09-12T20:16:10.44  653170575
2021-09-12T15:03:50.60  653151835
2021-09-12T13:55:16.45  653147721
2021-09-12T12:19:20.44  653141965
2021-09-12T10:10:11.73  653134216
2021-09-12T07:28:07.46  653124492
2021-09-12T06:51:13.22  653122278
2021-09-12T05:14:07.84  653116452
2021-09-11T02:36:38.24  653093506
2021-09-11T20:22:59.04  653084584
2021-09-11T20:05:46.22  653083551
2021-09-11T18:54:36.05  653079281
2021-09-11T17:01:09.77  653072474
2021-09-11T16:50:03.83  653071808
2021-09-11T16:36:57.91  653071022
2021-09-11T15:26:11.55  653066776
2021-09-11T15:15:25.44  653066130
2021-09-11T15:03:00.55  653065385
2021-09-11T13:27:33.85  653059658
2021-09-11T11:53:57.29  653054042
2021-09-11T10:42:51.85  653049776
2021-09-11T05:32:38.65  653031163
2021-09-11T03:02:28.36  653022153

Fermi GBM will not report on future triggers from this event.

The spectral analysis results presented above are preliminary. We encourage multi-wavelength
observations to follow-up this most recent activation.

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"

A. Ursi (INAF/IAPS), E. Menegoni, L. Foffano (INAF/IAPS), V. Fioretti
(INAF/OAS-Bologna), C. Pittori, F. Verrecchia (SSDC, and INAF/OAR), M.
Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C.
Casentini, Y. Evangelista, L. Pacciani, G. Piano (INAF/IAPS), F. Lucarelli
(SSDC, and INAF/OAR), A. Bulgarelli, F. Fuschino, N. Parmiggiani
(INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University),
M. Pilia, A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ.
Trieste and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of
the AGILE Team:

The AGILE satellite clearly detected the two bright bursts from the
SGR1935+2154, at T1 = 2021-09-10 00:45:47 s (UTC), reported by Konus-Wind
(GCN #30804
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 ), Fermi GBM (GCN #30806
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 ), and GECAM (GCN #30822
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 ), and at T2 =
2021-09-12 20:16:10 s (UTC), reported by Fermi GBM (GCN #30831
Loading...
 
 ).

The bursts are clearly visible in the AGILE scientific ratemeters of the
SuperAGILE (SA; 20-60 keV) and AntiCoincidence (AC; 50-200 keV) detectors.

The first event lasted about 2 s and it released a total number of 560
counts in the SA detector (above a background rate of 65 Hz), and 8730
counts in the AC detector (above a background rate of 3450 Hz). The AGILE
ratemeter light curves can be found at
http://www.agilescienceapp.it/notices/burst210910_AGILE_RM.png . At T1, the
SGR1935+2154 was 150 deg off-axis for AGILE.

The second event lasted 2 s and it released a total number of 620 counts in
the SA detector (above a background rate of 100 Hz), and 8170 counts in the
AC detector (above a background rate of 3500 Hz). The AGILE ratemeter light
curves can be found at
http://www.agilescienceapp.it/notices/burst210912_AGILE_RM.png . At T2, the
SGR1935+2154 was 37 deg off-axis for AGILE.

Additional analysis of AGILE data is in progress.

A. Ridnaia, S. Golenetskii, D. Frederiks, M. Ulanov,
D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

Since the last KW GCN on the ongoing SGR 1935+2154 activity
(Ridnaia et al., GCN 30803
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 ) the instrument triggered on
four bright bursts from the source.

The following is a list of the Konus-Wind triggers with preliminary
estimates of the burst fluences and peak fluxes.
------------------------------------------------------------------
#  Date       T0(KW) s UT                  Fl*           PF**
------------------------------------------------------------------
1 20210911 54406.825 s UT(15:06:46.825)  5.38 +/-0.15  22.6 +/-1.6
2 20210911 61274.025 s UT(17:01:14.025)  7.84 +/-0.21  18.5 +/-1.4
3 20210912 24677.185 s UT(06:51:17.185)  4.96 +/-0.14  26.6 +/-1.7
4 20210912 28904.121 s UT(08:01:44.121)  1.25 +/-0.02  17.0 +/-1.4
------------------------------------------------------------------
*  -  Fluence (20-500 keV) in units of 1e-6 erg/cm2

** - Peak Flux (20-500 keV) on 16-ms time scale
        in units of 1e-6 erg/cm2/s

The time-averaged spectra of the bursts are well fit in the
20 - 200 keV range by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with the following parameters:
------------------------------------------------------------------
#   T100   Tbeg-Tend         alpha            Ep(keV)    chi2/dof
------------------------------------------------------------------
1  0.392   0 - 0.256    0.47(-0.32,+0.33)    42(-2,+2)     30/20
2  1.243   0 - 8.448    0.40(-0.37,+0.39)    37(-2,+1)     36/28
3  0.452   0 - 0.256    0.20(-0.35,+0.37)    38(-2,+2)     17/19
4  1.600   0 - 8.448   -0.10(-0.21,+0.22)    35(-1,+1)     43/29
------------------------------------------------------------------
The emission in all bursts is seen up to ~200 keV.

The Konus-Wind light curves of the bursts are available at
http://www.ioffe.ru/LEA/SGRs/210911_T54406/
http://www.ioffe.ru/LEA/SGRs/210911_T61274/
http://www.ioffe.ru/LEA/SGRs/210912_T24677/
http://www.ioffe.ru/LEA/SGRs/210912_T28904/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

A. Ridnaia, D. Frederiks, S. Golenetskii, A. Lysenko,
D. Svinkin, A. Tsvetkova,  M. Ulanov, and T. Cline
on behalf of the Konus-Wind team, report:

A short, soft, SGR-like burst
triggered Konus-Wind on 2021 September 22 at
T0=72739.639 s UT (20:12:19.639).

The Konus-Wind ecliptic latitude response is consistent
with the SGR 1935+2154 position. So, taking in account
the ongoing bursting activity of this source, burst
time history, and softness of its spectrum (as observed
by Konus-Wind), we suggest that this burst is likely
originated from SGR 1935+2154.

The burst light curve shows a single pulse
started at ~T0-100 ms with a total duration of ~172 ms.
The emission is seen up to ~200 keV.

The Konus-Wind light curve of this burst is available at
http://www.ioffe.ru/LEA/SGRs/210922_T72739/

As observed by Konus-Wind, the burst
had a fluence of 1.46(-0.08,+0.08)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0+0.024 s,
of 1.59(-0.16,+0.16)x10^-5 erg/cm2/s
(both in the 20 - 500 keV energy range).

The spectrum of the burst
(measured from T0 to T0+0.064 s)
is best fit in the 20 - 200 keV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.13(-0.76,+0.85)
and Ep = 37(-6,+4) keV (chi2 = 12/14 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

Aaron Tohuvavohu (U Toronto), James DeLaunay (PSU), Gayathri Raman
(PSU), Jamie A. Kennea (PSU)  report:

Swift/BAT did not localize SGR 1935+2154 (T0:  2021-10-01 00:04:04.3
UTC, Fermi/GBM trigger #  654739449) onboard.

The Fermi/GBM notice, distributed in near real-time, triggered the
Swift Mission Operations Center operated Gamma-ray Urgent Archiver for
Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).

Upon trigger by this notice, GUANO sent a command to the Swift Burst
Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from
[-50,+150] seconds around the time of the burst. All the requested
event mode data was delivered to the ground.

The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu, in prep),
detects a burst and localizes it to the position of SGR 1935+2154.
The burst is detected in BAT with a duration of less than 64 ms.

This position is consistent with the Ferm/GBM localization.

GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.

A live reporting of Swift/BAT event data recovered by GUANO can be
found at: https://www.swift.psu.edu/guano/

A. Ursi (INAF/IAPS), C. Pittori, F. Verrecchia (SSDC, and INAF/OAR), G.
Piano, E. Menegoni, L. Foffano (INAF/IAPS), V. Fioretti (INAF/OAS-Bologna),
M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo,
C. Casentini, Y. Evangelista, L. Pacciani (INAF/IAPS), F. Lucarelli (SSDC,
and INAF/OAR), A. Bulgarelli, F. Fuschino, N. Parmiggiani
(INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University),
M. Pilia, A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ.
Trieste and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of
the AGILE Team:

The AGILE satellite clearly detected a bright burst from the SGR1935+2154,
at T0 = 2021-12-24 03:42:34 s (UTC), reported by Fermi GBM (Fermi GBM
Trigger bn211224155).

The burst is clearly visible in the AGILE scientific ratemeters of the
SuperAGILE (SA; 20-60 keV) and AntiCoincidence (AC; 50-200 keV) detectors.

The event lasted about 2 s and it released a total number of 360 counts in
the SA detector (above a background rate of 110 Hz), and 9250 counts in the
AC detector (above a background rate of 2960 Hz). The AGILE ratemeter light
curves can be found at
http://www.agilescienceapp.it/notices/SGR1935+2154_AGILE_RM.png . At T0,
the SGR1935+2154 was 46 deg off-axis for AGILE.

Additional analysis of AGILE data is in progress.

A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline
on behalf of the Konus-Wind team, report:

The very bright burst from SGR 1935+2154
(AGILE observations: Ursi et al., GCN Circ. 31296
Loading...
 
 ;
Swift-BAT detection: Palmer et al., ATel #15141)
triggered Konus-Wind at T0=13350.516 s UT (03:42:30.516)
on 2021 December 24.

The light curve shows a single pulse with a sharp(<10 ms) rise
and a total duration of ~1.3 s.
The emission is seen up to ~250 keV

The Konus-Wind light curve of this SGR is available at
http://www.ioffe.ru/LEA/SGRs/211224_T13350/

As observed by Konus-Wind, the burst
had a fluence of 1.09(-0.02,+0.02)x10^-5 erg/cm2,
and a 16-ms peak flux, measured from T0+0.640 s,
of 1.33(-0.09,+0.09)x10^-5 erg/cm2/s
(both in the 20 - 500 keV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+8.448 s)
is best fit in the 20 - 250 keV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = 0.32(-0.26,+0.27)
and Ep = 36(-1,+1) keV (chi2 = 35/29 dof).
The 2BB fit to this spectrum yields
the cool BB temperature kT1 = 5.2 (-1.5,+1.9) keV
and the hot BB temperature kT2 = 11.3 (-0.6,+1.3) keV
(chi2=37/28 dof).

The rather long duration of the burst along with the
large measured energy fluence put the burst in the class
of "intermediate" SGR bursts. Among 43 bright bursts
from SGR 1935+2154 detected by KW so far this event is
the fourth most fluent. The measured spectral
parameters are in typical range for bright short and
intermediate SGR bursts.

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

Y. Q. Zhang, S. L. Xiong, C. Cai, S. Xiao, P. Zhang, 
C. Y. Li, S. L. Xie, X. Y. Zhao, Y. Huang, X. Y. Song,
J. C. Liu,  Y. Zhao, Z. W. Guo, C. Zheng, W. C. Xue, C. W. Wang, 
Q. B. Yi, B. X. Zhang,  W. X. Peng, R. Qiao, D. Y. Guo, X. B. Li, 
X. Ma, L. M. Song, P. Wang, J. Wang, Z. Zhang, S. J. Zheng, W. Chen, 
J. J. He, G. Y. Zhao, Y. Q. Du, H. Wu, J. Liang, Q. Luo, X. L. Zhang, 
H. M. Zhang, Z. H. An, M. Gao, K. Gong, B. Li, C. Li, J. H. Li, 
X. Q. Li, Y. G. Li, X. H. Liang, X. J. Liu, Y. Q. Liu, X. L. Sun, 
Y. L. Tuo, J. Z. Wang, X. Y. Wen, Y. B. Xu, Y. P. Xu, S. Yang, 
C. Y. Zhang, D. L. Zhang, Fan Zhang, Fei Zhang,
X. Zhou, F. J. Lu, S. N. Zhang (IHEP)
report on behalf of GECAM team:

During the commissioning phase, GECAM-B was triggered in-flight by
a short burst (trig# 95135774) at 2022-01-06T02:36:14.100 UTC (T0).
Its alert data was promptly downlinked to the ground through the
short message service of BeiDou Navigation Satellite System (BDS).
The time latency of the first BeiDou message relative to the trigger time
is about 1 minute.
 
According to the GECAM-B light curves in about 30-1020 keV, this burst mainly
consists of a single pulse with a duration about 50 ms.

The location is consistent with SGR J1935+2154 within the error.

The GECAM light curve could be found here:
http://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_lc_grd_all_combine_95135774.png

As the detailed science data are downloaded, all analyses would be improved.

Please note that all GECAM results here are preliminary. The final analysis
will be published in journal papers or GECAM online catalog.

Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor
(GECAM) mission consists of two small satellites (GECAM-A and GECAM-B) in
Low Earth Orbit (600 km, 29 deg), launched on Dec 10, 2020 (Beijing Time),
which was funded by the Chinese Academy of Sciences (CAS).

A. Ursi (INAF/IAPS), C. Pittori, F. Verrecchia (SSDC, and INAF/OAR), M.
Cardillo (INAF/IAPS), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A.
Argan, M. Cardillo, C. Casentini, Y. Evangelista, E. Menegoni, L. Foffano,
L. Pacciani, G. Piano (INAF/IAPS), F. Lucarelli (SSDC, and INAF/OAR), A.
Bulgarelli, F. Fuschino, N. Parmiggiani, V. Fioretti (INAF/OAS-Bologna), M.
Marisaldi (INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois
(INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ. Trieste and INFN
Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of the AGILE Team:

The AGILE satellite detected a short burst at T0 = 2022-01-12 08:39:25
(UTC), compatible with the fourth bright burst from the SGR1935+2154
recently reported by GECAM (GCN #31443
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 ).

The event is clearly visible in the AGILE scientific ratemeters of the
SuperAGILE (SA; 20-60 keV) and AntiCoincidence (AC; 50-200 keV) detectors.
The burst released a total number of 117 counts in the SA detector (above a
background rate of 100 Hz), and 4938 counts in the AC detector (above a
background rate of 3575 Hz). The AGILE ratemeter light curves can be found
at http://www.agilescienceapp.it/notices/SGR220112_AGILE_RM.png .

Additional analysis of AGILE data is in progress.

A. Ridnaia, D. Frederiks, M. Ulanov, D. Svinkin,
A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

Since the last KW GCN on the ongoing SGR 1935+2154 activity
(Ridnaia et al., GCN 31325
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 ) the instrument triggered on
thirteen bright bursts from the source.

The following is a list of the Konus-Wind triggers.
---------------------------------------------
#     Date       T0(KW) s        UT
---------------------------------------------
1   20211229  60082.391 s UT (16:41:22.391)
2   20220111  61551.690 s UT (17:05:51.690)
3   20220112  31161.806 s UT (08:39:21.806)
4   20220113  29375.444 s UT (08:09:35.444)
5   20220113  46378.912 s UT (12:52:58.912)
6   20220113  80750.270 s UT (22:25:50.270)
7   20220114  33622.126 s UT (09:20:22.126)
8   20220114  58119.186 s UT (16:08:39.186)
9   20220114  71808.322 s UT (19:56:48.322)
10  20220115  30352.115 s UT (08:25:52.115)
11  20220115  62515.176 s UT (17:21:55.176)
12  20220115  70649.225 s UT (19:37:29.225)
13  20220116  50974.968 s UT (14:09:34.968)
---------------------------------------------
The bursts have durations (~0.2-0.9 s),
energy fluences (0.9-5.9)x10^-6 erg/cm2,
and spectral hardness (Ep ~ 20-45 keV)
typical of bright short bursts from SGR 1935+2154
observed by KW previously.

The detailed analysis of these bursts will be presented
in the dedicated paper.

A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov,
and A.B. Sanin on behalf of the HEND/Mars Odyssey teams,

D. Svinkin, A. Ridnaia, D. Frederiks, A. Lysenko,
and T. Cline on behalf of the Konus-Wind team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

A very bright, short-duration, soft burst has been detected by
Konus-Wind, INTEGRAL (SPI-ACS), and Mars-Odyssey (HEND), so far,
at about 35470 s UT (09:51:10).

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   293.659 (19h 34m 38s) +21.934 (+21d 56' 03")
  Corners:
   293.077 (19h 32m 18s) +22.236 (+22d 14' 11")
   293.139 (19h 32m 33s) +22.259 (+22d 15' 34")
   294.235 (19h 36m 56s) +21.626 (+21d 37' 33")
   294.173 (19h 36m 41s) +21.604 (+21d 36' 15")
  ---------------------------------------------
The error box area is 213 sq. arcmin, and its maximum
dimension is 74 arcmin (the minimum one is 5 arcmin).
The Sun distance was 44 deg.

This box may be improved.

The position of SGR 1935+2154 is inside the box
at 4.6 arcmin from the box center.

Given the positional coincidence of this burst with SGR 1935+2154, its
time history, and softness of its spectrum  (as observed by Konus-Wind),
we conclude this burst is likely originated from SGR 1935+2154.

A triangulation map is posted at
http://www.ioffe.ru/LEA/SGRs/220120_T35475/IPN/

The time history and spectrum will be given in forthcoming GCN Circulars.

A. Ridnaia, D. Frederiks, M. Ulanov, D. Svinkin,
A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

The bright burst from SGR 1935+2154
(IPN triangulation: Kozyrev et al., GCN Circ. 31512
Loading...
 
 )
triggered Konus-Wind at T0=35475.962 s UT (09:51:15.962)
on 2021 January 20.

The light curve shows a single pulse with a sharp(<10 ms) rise
and a total duration of ~1.2 s.
The emission is seen up to ~200 keV.

The Konus-Wind light curve of this burst is available at
http://www.ioffe.ru/LEA/SGRs/220120_T35475/

As observed by Konus-Wind, the burst
had a fluence of 7.54(-0.19,+0.19)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0+0.012 s,
of 1.08(-0.11,+0.11)x10^-5 erg/cm2/s
(both in the 20 - 500 keV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+1.024 s)
is best fit in the 20 - 200 keV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = 0.17(-0.26,+0.27)
and Ep = 43(-1,+1) keV (chi2 = 44/25 dof).

The rather long duration of the event along with the
large measured energy fluence put the burst in the class
of "intermediate" SGR flares.

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

A. Ursi (INAF/IAPS), F. Longo (Univ. Trieste and INFN Trieste), F.
Verrecchia, C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and
Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C. Casentini, Y.
Evangelista, E. Menegoni, L. Foffano, L. Pacciani, G. Piano, M. Romani
(INAF/IAPS), F. Lucarelli (SSDC, and INAF/OAR), A. Bulgarelli, V. Fioretti,
F. Fuschino, N. Parmiggiani (INAF/OAS-Bologna), M. Marisaldi
(INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois
(INAF/OA-Cagliari), I. Donnarumma (ASI), , A. Giuliani (INAF/IASF-Mi),
report on behalf of the AGILE Team:

The AGILE satellite clearly detected the bright burst from the
SGR1935+2154, at T0 = 2022-01-20 09:51:16 s (UTC), reported by Konus-Wind
(GCN #31513
Loading...
 
 ) and triangulated by IPN (GCN #31512
Loading...
 
 ).

The burst is clearly visible in the AGILE scientific ratemeters of the
SuperAGILE detector (SA; 20-60 keV) and in all the five panels of the
AntiCoincidence system (AC Top, 50-200 keV; AC Lat, 80-200 keV). The event
released a total number of 289 counts in the SA detector (above a
background rate of 115 Hz), and 5100 counts in the AC detector (above a
background rate of 3400 Hz). The AGILE ratemeter light curves can be found
at http://www.agilescienceapp.it/notices/SGR1935+2154_220120_AGILE_RM.png .
At T0, the SGR1935+2154 was 110 deg off-axis for AGILE.

Additional analysis of AGILE data is in progress.

A.Ridnaia, D. Frederiks, A.Lysenko, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

A short, soft, SGR-like burst
triggered Konus-Wind on 2022 May 25 at
T0=25816.58 s UT (07:10:16.580).

The Konus-Wind ecliptic latitude response is consistent
with the SGR 1935+2154 position. So, taking in account
the ongoing bursting activity of this source, burst
time history, and softness of its spectrum (as observed
by Konus-Wind), we suggest that this burst is likely
a SGR flare originated from SGR 1935+2154.

The burst light curve shows a single pulse
started at ~T0-72 ms with a total duration of ~194 ms.
The emission is seen up to ~200 keV.

The Konus-Wind light curve of this burst is available at
http://www.ioffe.ru/LEA/SGRs/220525_T25816/

As observed by Konus-Wind, the burst
had a fluence of 2.55(-0.10,+0.10)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0-0.014 s,
of 2.08(-0.16,+0.16)x10^-5 erg/cm2/s
(both in the 20 - 500 keV energy range).

The spectrum of the burst
(measured from T0 to T0+0.192 s)
is best fit in the 20 - 200 keV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = 0.22(-0.54,+0.61)
and Ep = 36(-3,+2) keV (chi2 = 20/18 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

A.Ridnaia, D. Frederiks, A.Lysenko, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The bright burst from SGR 1935+2154
triggered Konus-Wind at T0=25915.887 s UT (07:11:55.887)
on 2022 June 16.

The light curve shows a single pulse with a sharp(<10 ms) rise
and a total duration of ~0.8 s.
The emission is seen up to ~200 keV.

The Konus-Wind light curve of this burst is available at
http://www.ioffe.ru/LEA/SGRs/220616_T25915/

As observed by Konus-Wind, the burst
had a fluence of 1.15(-0.03,+0.03)x10^-5 erg/cm2,
and a 16-ms peak flux, measured from T0+0.070 s,
of 2.32(-0.16,+0.16)x10^-5 erg/cm2/s
(both in the 20 - 500 keV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+0.256 s)
is best fit in the 20 - 500 keV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.35(-0.26,+0.28)
and Ep = 39(-2,+2) keV (chi2 = 17/22 dof).

The rather long duration of the burst along with the
large measured energy fluence put the burst in the class
of "intermediate" SGR bursts. Among 61 bright bursts
from SGR 1935+2154 detected by KW so far this event is
the fourth most fluent. The measured spectral
parameters are in typical range for bright short and
intermediate SGR bursts.

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

C. Malacaria (ISSI), P. Veres (UAH) and O. Roberts (USRA) 
report on behalf of the Fermi-GBM Team:

"The Fermi Gamma-ray Burst Monitor (GBM) triggers 
221013391/687345829 at 09:23:44.18 UT,
221013376/687344475 at 09:01:10.88 UT, 
221013334/687340841 at 08:00:36.49 UT, 
221013304/687338292 at 07:18:07.15 UT,
221013295/687337536 at 07:05:31.76 UT, 
221013037/687315163 at 00:52:38.25 UT
on 13 October 2022 and
221012977/687310007 at 23:26:42.31 UT,
221012906/687303863 at 21:44:18.47 UT,
221012874/687301134 at 20:58:49.99 UT,
221012773/687292428 at 18:33:43.51 UT,
221012709/687286852 at 17:00:47.29 UT,
on 12 October 2022
all tentatively classified as a GRB, are in fact not due to a GRB.

These triggers are due to a SGR 1935+2154 which, 
as recently announced (Mereghetti et al., GCN #32706
Loading...
 
  and 
Roberts et al. GCN #32708
Loading...
 
 ), is undergoing high bursting activity.

For Fermi GBM data and info, please visit
the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"

P. Veres (UAH), S. Lesage (UAH) and C. Malacaria (ISSI)

report on behalf of the Fermi-GBM Team:

"The Fermi Gamma-ray Burst Monitor (GBM) triggers

221013599/687363763 at 14:22:38.10,
221013646/687367836 at 15:30:31.54,
221013862/687386508 at 20:41:43.00,
on 13 October 2022 and

221014098/687406838 at 02:20:33.52,
221014238/687418940 at 05:42:15.46,
221014300/687424353 at 07:12:28.77,
221014309/687425087 at 07:24:42.11,
221014487/687440524 at 11:41:59.73,
221014521/687443446 at 12:30:41.22,
221014556/687446436 at 13:20:31.77,
221014579/687448456 at 13:54:11.01,
221014711/687459861 at 17:04:16.62,
221014719/687460494 at 17:14:49.05
on 14 October 2022

all tentatively classified as a GRB, are in fact not due to a GRB.

These triggers are due to a SGR 1935+2154 which,
as recently announced (Mereghetti et al., GCN #32706
Loading...
 
  and
Roberts et al. GCN #32708
Loading...
 
 ), is undergoing high bursting activity.

For Fermi GBM data and info, please visit
the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"

Since the last KW GCN on the ongoing SGR 1935+2154 activity
(Ridnaia et al., GCN 32204
Loading...
 
 ) the instrument triggered on
six bright bursts from the source.

The following is a list of the Konus-Wind triggers with preliminary
estimates of the burst fluences and peak fluxes.
------------------------------------------------------------------
#  Date       T0(KW) s UT                  Fl*           PF**
------------------------------------------------------------------
1 20221012 56552.646 s UT(15:42:32.646)  3.09 +/-0.10  15.2 +/-1.3
2 20221013  7366.180 s UT(02:02:46.180)  3.30 +/-0.11  16.9 +/-1.4
3 20221013 81690.645 s UT(22:41:30.645)  5.75 +/-0.22  19.6 +/-1.5
4 20221014 25949.934 s UT(07:12:29.934)  1.92 +/-0.08  16.0 +/-1.5
5 20221014 50052.142 s UT(13:54:12.142)  0.71 +/-0.06  14.7 +/-1.8
6 20221014 61721.260 s UT(17:08:41.260)  1.88 +/-0.18  20.3 +/-2.4
------------------------------------------------------------------
*  -  Fluence (20-500 keV) in units of 1e-6 erg/cm2

** - Peak Flux (20-500 keV) on 16-ms time scale
        in units of 1e-6 erg/cm2/s

The time-averaged spectra of the bursts are well fit in the
20 - 500 keV range by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with the following parameters:
------------------------------------------------------------------
#   T100   Tbeg-Tend         alpha            Ep(keV)    chi2/dof
------------------------------------------------------------------
1  0.434   0 - 0.256    0.54(-0.61,+0.68)    29(-3,+2)     12/19
2  0.330   0 - 0.256   -0.20(-0.38,+0.41)    33(-3,+2)     24/20
3  0.424   0 - 8.448   -0.05(-0.38,+0.41)    39(-2,+2)     48/40
4  0.202   0 - 0.192   -1.00(-0.48,+0.54)    27(-8,+5)     20/20
5  0.168   0 - 0.128   -0.5 fixed            25(-3,+4)     13/16
6  0.516   0 - 8.448   -1.36(-0.62,+1.29)    17(-10,+11)   48/40
------------------------------------------------------------------
The emission in all bursts is seen up to ~200 keV.

The Konus-Wind light curves of the bursts are available at
http://www.ioffe.ru/LEA/SGRs/221012_T56552/
http://www.ioffe.ru/LEA/SGRs/221013_T07366/
http://www.ioffe.ru/LEA/SGRs/221013_T81690/
http://www.ioffe.ru/LEA/SGRs/221014_T25949/
http://www.ioffe.ru/LEA/SGRs/221014_T50052/
http://www.ioffe.ru/LEA/SGRs/221014_T61721/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

D. Frederiks, A. Ridnaia, D. Svinkin, A. Lysenko,
M. Ulanov (all - Ioffe Institute), and A. Tsvetkova
(Ioffe Institute/University of Cagliari), report:

Konus-Wind (KW) detected a short X-ray burst on 2022-10-14
in time interval from 19:21:39.205 UTC to 19:21:42.149 UTC.

Corrected for the propagation from low-Earth orbit to Wind (~1.05 s),
the burst arrival time is consistent with the detection time
of a bright short X-ray burst from SGR 1935+2154, reported
by GECAM and HEBS (Atel #15682), which, in turn, is consistent
with the dedispersed topocentric time of a bright radio burst
detected from SGR 1935+2154 by CHIME (Atel #15681).

The event was detected by KW in the waiting mode and no detailed
information on its temporal structure is available.
The emission is seen in two instrument's energy bands:
G1(20-80 keV) and G2 (80-320 keV), while no statistically
significant signal is visible above 320 keV.

A time-averaged spectrum of the burst can be described
in the 20-1300 keV range by a power law with exponential
cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with the peak energy Ep of (40 �� 6) keV, which is slightly
higher than a typical Ep of multiple bright SGR 1935+2154
bursts detected by KW recently (GCN Circ. 32768
Loading...
 
 ).
We also note that the October 14 burst Ep is about twice
as lower as the peak energy (~85 keV) measured by KW for
the much radio-brighter event SGR/FRB200428 from the same
magnetar (Ridnaia et al. 2021, NatAstr. 5, 372).
 From the KW detection, we estimate the total 20-500 keV fluence
of the burst to (5.7 �� 0.6)x10^-7 erg/cm2, about two times
lower than that of SGR/FRB200428.

This GCN circular duplicates ATel #15686.

A.Ridnaia, D. Frederiks, A.Lysenko, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

A short, soft, SGR-like burst
triggered Konus-Wind on 2022 October 17 at
T0=40483.010 s UT (11:14:43.010).

The Konus-Wind ecliptic latitude response is consistent
with the SGR 1935+2154 position. So, taking in account
the ongoing bursting activity of this source, burst
time history, and softness of its spectrum (as observed
by Konus-Wind), we suggest that this burst is likely
a SGR flare originated from SGR 1935+2154.

The burst light curve shows a single pulse
started at ~T0-56 ms with a total duration of ~202 ms.
The emission is seen up to ~200 keV.

The Konus-Wind light curve of this burst is available at
http://www.ioffe.ru/LEA/SGRs/221017_T40483/

As observed by Konus-Wind, the burst
had a fluence of 2.16(-0.10,+0.10)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0-0.006 s,
of 2.84(-0.22,+0.22)x10^-5 erg/cm2/s
(both in the 20 - 500 keV energy range).

The spectrum of the burst
(measured from T0 to T0+0.192 s)
is best fit in the 20 - 500 keV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.71(-0.50,+0.57)
and Ep = 33(-7,+5) keV (chi2 = 15/19 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), F. Munz, N. Husarikova, J.-P. Breuer, M. Topinka, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropoli
 tan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration.

The recently active SGR 1935+2154 (Fermi-GBM detection: Veres et al., GCN 32764
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 , Konus-Wind detection: Ridnaia et al., GCN 32768
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 ) was detected by the GRBAlpha 1U CubeSat (Pal et al. Proc. SPIE 2020). This is the first time an SGR was detected by GRBAlpha.

The 11 sigma detection was confirmed at the peak time 2022-10-14 07:12:27.8 UTC. The temporal resolution of the observation was 4 s and the light curve obtained by GRBAlpha shows an excess in one bin.

The light curve obtained by GRBAlpha is available here:
https://grbalpha.konkoly.hu/static/share/SGR1935+2154_GCN.pdf

GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). Its detector consists of a 75 x 75 x 5 mm^3 CsI(Tl) scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, we are continuously upgrading the on-board data acquisition software stack. The ground segment is also supported by the radio amateur community, and it takes advantage of the SatNOGS network for increased data downlink volume.

J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory),�� N. Werner (Masaryk 
U.), M. Ohno (Hiroshima U.),�� L. Meszaros, B. Csak (Konkoly 
Observatory), H. Takahashi (Hiroshima U.), F. Munz, M. Dafcikova, N. 
Husarikova, M. Topinka, F. Hroch, J.-P. Breuer (Masaryk U.), J. Hudec, 
J. Kapus, M. Frajt, M. Rezenov (Spacemanic s.r.o), R. Laszlo 
(Needronix), G. Galgoczi (Wigner Research Center/Eotvos U.), N. Uchida 
(ISAS/JAXA), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), Y. Fukazawa, K. 
Hirose, H. Matake (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe 
(Rikkyo U.), L. L. Kiss (Konkoly Observatory),�� T. Mizuno (Hiroshima 
U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), K. Torigoe 
(Hiroshima U.), P. Svoboda, V. Daniel, J. Dudas, M. Junas, J. Gromes 
(VZLU), I. Vertat (FEL ZCU)�� -- the VZLUSAT-2/GRB payload collaboration.

The recently active SGR 1935+2154 (Fermi-GBM detection: Malacaria et 
al., GCN Circ. 32737
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 , Konus-Wind detection: Ridnaia et al., GCN Circ. 
32768
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 ) was detected by the GRB detector module no. 1 on board of the 
VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz/en/).

The list of detected SGR bursts with their significance is:

Date and time in UTC�������� SNR
2022-10-12 23:26:41���������� 17.6
2022-10-13 02:02:43���������� 16.5
2022-10-13 22:41:28���������� 125

The light curves obtained by VZLUSAT-2 are available here:
https://vzlusat2.konkoly.hu/static/share/SGR_1935_2154_GCN_VZLUSAT-2.pdf

GRB detectors on VZLUSAT-2 are a demonstration payload for a future 
CubeSats constellation (Werner et al. Proc. SPIE 2018). Two GRB modules 
of VZLUSAT-2 are placed in a perpendicular manner and each consists of a 
75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the 
energy range from ~30 keV to ~1000 keV. VZLUSAT-2 was launched on 2022 
January 13 from Cape Canaveral.

J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory),�� N. Werner�� (Masaryk 
U.), M. Ohno (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), 
H. Takahashi (Hiroshima U.), F. Munz, M. Dafcikova, N. Husarikova, M. 
Topinka, F. Hroch, J.-P. Breuer (Masaryk U.), J. Hudec, J. Kapus, M. 
Frajt, M. Rezenov (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix 
s.r.o), G. Galgoczi (Wigner Research Center/Eotvos U.), N. Uchida 
(ISAS/JAXA), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), Y. Fukazawa, K. 
Hirose, H. Poon, H. Matake (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. 
Ichinohe (Rikkyo U.), L. L. Kiss (Konkoly Observatory),�� T. Mizuno 
(Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), K. 
Torigoe (Hiroshima U.), P. Svoboda, V. Daniel, J. Dudas, M. Junas, J. 
Gromes (VZLU), I. Vertat (FEL ZCU), T. Urbanec, M. Kasal, A. Povalac 
(Brno U. of Technology), M. Smelko, P. Hanak, P. Lipovsky (Technical U. 
of Kosice), T. Bozoki, G. Dalya, G. Friss, K. Kapas, J. Takatsy (Eotvos 
U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. 
Tokyo), T. Kano (U. Michigan) -- the VZLUSAT-2/GRB payload and GRBAlpha 
collaborations

We report a joint detection of the recently active SGR 1935+2154 by the 
GRB detector on board of VZLUSAT-2 3U CubeSat 
(https://www.vzlusat2.cz/en/) and 1U GRBAlpha CubeSat (Pal et al. Proc. 
SPIE 2020). The bursting activity was also observed by Insight-HXMT (C. 
K. Li et al., ATel #15698), INTEGRAL/SPI-ACS, and�� Konus-Wind (D. 
Svinkin priv. comm.). Non-detection by Fermi/GBM can be explained by the 
Earth occultation of�� SGR 1935+2154 (P. Veres priv. comm.).

The list of distinct peaks measured by the GRB detector module no. 1 on 
board of the VZLUSAT-2 with their background-subtracted peak rates in 
~40-890 keV band and significance is:

Date and time in UTC�������� peak rate (cnt/s)�� �� �� SNR
2022-10-14 17:26:07.5���������������������������������� 220�������� 12.9
2022-10-14 17:27:36.5�������������������������������� 1170�������� 62.6
2022-10-14 17:27:39.5���������������������������������� 931�������� 48.8
2022-10-14 17:27:43.5���������������������������������� 159���������� 8.1
2022-10-14 17:27:49.5���������������������������������� 205�������� 10.0

The light curves obtained by VZLUSAT-2 and GRBAlpha are available here:
https://grbalpha.konkoly.hu/static/share/SGR_1935_2154_GCN_GRBAlpha_VZLUSAT_2.pdf

GRB detectors on VZLUSAT-2 are a demonstration payload for a future 
CubeSats constellation (Werner et al. Proc. SPIE 2018). Two GRB modules 
of VZLUSAT-2 are placed in a perpendicular manner and each consists of a 
75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the 
energy range from ~30 keV to ~1000 keV. VZLUSAT-2 was launched on 2022 
January 13 from Cape Canaveral.

GRBAlpha, launched on 2021 March 22, is a demonstration mission for a 
future CubeSat constellation (Werner et al. Proc. SPIE 2018). Its 
detector consists of a 75 x 75 x 5 mm^3 CsI(Tl) scintillator read out by 
a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To 
increase the duty cycle and the downlink rate, we are continuously 
upgrading the on-board data acquisition software stack. The ground 
segment is also supported by the radio amateur community, and it takes 
advantage of the SatNOGS network for increased data downlink volume.

We thank P. Veres and D. Svinkin for providing us with information which 
helped us to associate our detection with SGR 1935+2154.

P. Veres (UAH)
reports on behalf of the Fermi-GBM Team:

"The Fermi Gamma-ray Burst Monitor (GBM) triggers

221015093/687492839 at 02:13:54.55,
on 15 October 2022 and

221017553/687705349 at 13:15:44.21
on 17 October 2022

all tentatively classified as a GRB, are in fact not due to a GRB.

These triggers are due to SGR 1935+2154 which recently underwent a
period of high bursting activity (Mereghetti et al., GCN #32706
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  and
Roberts et al. GCN #32708
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 )


For Fermi GBM data and information, please visit
the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"

G. Waratkar (IITB), V. Bhalerao (IITB), A. Vibhute (IUCAA), D. 
Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. 
Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 
2021, JApA, 42, 73) showed the detection of bursts from SGR 1935+2154 as 
follows.

--------------------------------------------------------------------
Time | Detected_by | GCN
--------------------------------------------------------------------
2022-10-12T15:14:04.13 | Fermi-GBM | 32708
2022-10-14T13:20:31.77 | Fermi-GBM | 32764
--------------------------------------------------------------------

We also report a forest of seven bright bursts within 15s from 
2022-10-14T17:27:33, that are likely related to SGR 1935+2154.

CZTI is built by a TIFR-led consortium of institutes across India, 
including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research 
Organisation funded, managed, and facilitated the project.

A.Ridnaia, D. Frederiks, A.Lysenko, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The bright burst from SGR 1935+2154
(Fermi-GBM detection: Wood, GCN Circ. 32922
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 )
triggered Konus-Wind at T0=57968.083 s UT (16:06:08.083)
on 2022 November 9.

The burst light curve shows a bright pulse
which starts at ~T0-0.246 s and has a duration of ~0.4 s.
The main pulse is followed, after a short period of
quiescence, by multiple weaker pulses in the interval
from ~T0+0.6 s to ~T0+1.3 s.
The emission is seen up to ~200 keV.

The Konus-Wind light curve of this burst is available at
http://www.ioffe.ru/LEA/SGRs/221109_T57968/

As observed by Konus-Wind, the burst
had a fluence of 2.37(-0.11,+0.11)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0-0.064 s,
of 1.35(-0.14,+0.14)x10^-5 erg/cm2/s
(both in the 20 - 500 keV energy range).

The spectrum of the burst
(measured from T0 to T0+0.192 s)
is best fit in the 20 - 500 keV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.02(-0.82,+0.92)
and Ep = 28(-6,+4) keV (chi2 = 29/17 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

A.Ridnaia, D. Frederiks, A.Lysenko, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

A bright burst from SGR 1935+2154
(also detected by Fermi-GBM (trigger 692607435)
and GECAM (both reported in GCN Notices))
triggered Konus-Wind at T0=25026.883 s UT (06:57:06.883)
on 2022 December 13.

The burst light curve shows a bright pulse,
which starts at ~T0-96 ms and has a total duration of ~142 ms.
The emission is seen up to ~200 keV.

The Konus-Wind light curve of this burst is available at
http://www.ioffe.ru/LEA/SGRs/221213_T25026/

As observed by Konus-Wind, the burst
had a fluence of 6.61(-0.48,+0.48)x10^-7 erg/cm2,
and a 16-ms peak flux, measured from T0-0.012 s,
of 1.31(-0.16,+0.16)x10^-5 erg/cm2/s
(both in the 20 - 500 keV energy range).

The spectrum of the burst
(measured from T0 to T0+0.064 s)
is best fit in the 20 - 500 keV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = 0.12(-1.06,+1.30)
and Ep = 37(-8,+4) keV (chi2 = 15/11 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.