GRB 220706A
GCN Circular 32329
Subject
GRB 220706A: Swift detection of a burst
Date
2022-07-06T16:27:19Z (3 years ago)
From
Antonino D'Ai at IASF-PA <antonino.dai@inaf.it>
A. D'Ai (INAF-IASFPA), E. Ambrosi (INAF-IASFPA),
V. D'Elia (SSDC & INAF-OAR), J.D. Gropp (PSU), J. A. Kennea (PSU),
N. J. Klingler (GSFC/UMBC/CRESSTII), S. Laha (GSFC/UMBC),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
T. M. Parsotan (GSFC/UMBC/CRESSTII), M. H. Siegel (PSU) and
M. A. Williams (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 16:09:14 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 220706A (trigger=1114937). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 0.587, -16.391 which is
RA(J2000) = 00h 02m 21s
Dec(J2000) = -16d 23' 28"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a complex structure
with a duration of about 50 sec. The peak count rate
was ~1400 counts/sec (15-350 keV), at ~1 sec after the trigger.
The XRT began observing the field at 16:10:57.0 UT, 102.8 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 0.60368, -16.41065 which is equivalent
to:
RA(J2000) = 00h 02m 24.88s
Dec(J2000) = -16d 24' 38.3"
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This
location is 91 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at https://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 (2.40 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 6.6
(+4.12/-3.33) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 107 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 expected extinction corresponding to E(B-V) of
0.025.
Burst Advocate for this burst is A. D'Ai (antonino.dai AT inaf.it).
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)
GCN Circular 32330
Subject
GRB 220706A: Prompt enhanced Swift-XRT position
Date
2022-07-06T16:57:59Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Using promptly downlinked XRT event data for GRB 220706A, we find an
enhanced XRT position of the afterglow: RA, Dec: 0.60455, -16.41107
which is equivalent to:
RA (J2000) = 00 02 25.09
Dec (J2000) = -16 24 39.9
with an uncertainty of 1.9 arcseconds (radius, 90% confidence).
Analysis of the promptly available data is online at
http://www.swift.ac.uk/sper/1114937.
Position enhancement is is described by Goad et al. (2007, A&A, 476,
1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular is an official product of the Swift-XRT team.
GCN Circular 32331
Subject
GRB 220706A: Zadko observatory - Gingin optical observations
Date
2022-07-06T17:57:05Z (3 years ago)
From
Bruce Gendre at UVI <bruce.gendre@gmail.com>
B. Gendre, E. Moore, J. A. Moore, F. Panther (OzGrav-UWA), A. Klotz
(IRAP-CNRS-OMP),
P. Thierry (Les Makes observatory), and D. Coward (OzGrav-UWA),
report:
We imaged the field of GRB 220706A detected by SWIFT
(trigger 1114937, D'Ai et al. GCN 32329) with the Zadko
robotic telescope (D=100cm) located at the observatory -
Gingin, Australia.
The observations started 157.6s after the GRB trigger
(123.9s after the notice). The elevation of the field
increased from 18 degrees above horizon and weather
conditions were good.
At the position of the X-ray afterglow reported by
Evans et al. (GCN 32330), we do not detect any source
using a clear filter.
t0+157.6s to t0+167.6s : R > 14.5
We co-added a series of long exposures:
t0+1414s to t0+1962s : R > 17.0
Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.
N.B. Galactic coordinates are lon= 73.7767 lat=-74.3612
This message may be cited.
GCN Circular 32332
Subject
Swift GRB 220706A: Global MASTER-Net observations report
Date
2022-07-06T22:45:23Z (3 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko,
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),
D. Buckley
(South African Astronomical Observatory),
O.A. Gres, N.M. Budnev
(Irkutsk State University, API),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov
(Blagoveschensk Educational State University)
MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 220706A ( A. D'Ai et al., GCN 32329) errorbox 22935 sec after notice time and 22975 sec after trigger time at 2022-07-06 22:32:09 UT, with upper limit up to 18.2 mag. The observations began at zenith distance = 71 deg. The sun altitude is -80.3 deg.
The galactic latitude b = -75 deg., longitude l = 76 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2023835
We obtain a following upper limits.
Tmid-T0 | Site |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________
23065 | MASTER-SAAO | C | 180 | 18.2 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 32333
Subject
GRB 220706A: Enhanced Swift-XRT position
Date
2022-07-06T23:58:49Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team.
Using 822 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 220706A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 0.60427, -16.41121 which is equivalent
to:
RA (J2000): 00h 02m 25.03s
Dec (J2000): -16d 24' 40.4"
with an uncertainty of 2.2 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 32335
Subject
GRB 220706A: Nanshan/NEXT optical upper limits
Date
2022-07-07T02:45:18Z (3 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
S.Q. Jiang (NAOC), Z.P. Zhu (NAOC,HUST), S.Y. Fu , X. Liu, D. Xu (NAOC),
X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the field of GRB 220706A detected by Swift (D'Ai et al., GCN
32329) using the NEXT-0.6m telescope located at Nanshan, Xinjiang,
China. We obtained 7x200 s frames in the Sloan r-band and 5x200 s frames
in the Sloan z-band, starting at 20:21:09 UT on 2022-07-06, i.e., 4.2 hr
after the BAT trigger.
No optical source is detected in our stacked images at the enhanced XRT
position (Goad et al., GCN 32333), with upper limits as follows:
T_mid-T0 (hr) Filter Upper limit(3-sigma)
4.41 r >20.7
4.79 z >18.8
calibrated with the nearby PanSTARRS field and not corrected for
Galactic extinction.
GCN Circular 32337
Subject
GRB 220706A: MAXI/GSC detection 84 minutes after the Swift Trigger
Date
2022-07-07T05:18:45Z (3 years ago)
From
Motoko Serino at Aoyama Gakuin U. <serino@phys.aoyama.ac.jp>
M. Serino, T. Sakamoto (AGU), W. Iwakiri (Chuo U.), H. Negoro (Nihon U.), Y. Kawakubo (LSU),
N. Kawai, M. Niwano, R. Hosokawa, Y. Imai, N. Ito, Y. Takamatsu (Tokyo Tech),
M. Nakajima, K. Kobayashi, M. Tanaka, Y. Soejima (Nihon U.),
T. Mihara, T. Kawamuro, S. Yamada, T. Tamagawa, M. Matsuoka (RIKEN),
S. Sugita, H. Hiramatsu, A. Yoshida (AGU),
Y. Tsuboi, J. Kohara (Chuo U.),
M. Shidatsu, M. Iwasaki (Ehime U.),
S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, M. Tominaga, T. Nagatsuka, T. Kurihara (JAXA),
Y. Ueda, S. Ogawa, K. Setoguchi, T. Yoshitake, K. Inaba (Kyoto U.),
H. Tsunemi (Osaka U.),
M. Yamauchi, T. Sato, R. Hatsuda, R. Fukuoka, Y. hagiwara, Y. Umeki (Miyazaki U.),
K. Yamaoka (Nagoya U.),
M. Sugizaki (NAOC)
report on behalf of the MAXI team:
The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray
transient source at 17:33:25 UT on 2022 July 6 at
(R.A., Dec) = (0.219 deg, -16.471 deg) (J2000)
This position was consistent with GRB 220607A (GCN #32329) and the scan transit
was 5051 sec after the BAT trigger time (T0).
The scan was not completed because the GSC HV turned off due to the high
latitude constraint. The preliminary observed flux was about 200 mCrab in
the 2 - 10 keV band.
The transient was also observed at the next scan transit (17:53, T0+6260s) and
the flux decayed to about 60 mCrab in the same energy band.
We note that Swift/XRT also detected bright X-ray flare around T0+5400s.
There was no significant excess flux in the previous transit at 16:00 UT
and in the third transit at 19:26 UT with an upper limit of 20 mCrab for each.
Since the X-ray flaring activity of this GRB was unusual, we encourage
multi-wavelength observations.
GCN Circular 32338
Subject
GRB 220706A: Optical observations from NOT
Date
2022-07-07T07:06:31Z (3 years ago)
From
Antonio de Ugarte Postigo at OCA <deugarte@oca.eu>
A. de Ugarte Postigo, (OCA), D.B. Malesani (Radboud Univ. and DAWN/NBI),
and A. Kasikov (NOT, Aarhus Univ, Univ. of Tartu) report on behalf of a larger
collaboration,
We observed the field of GRB 220706A (D���Ai et al. GCN 32329) with AlFOSC
on the 2.5m NOT telescope at Roque de los Muchachos Observatory (La
Palma, Spain). The observation started at 04:33 UT (11.68 hrs after the burst)
and consisted on 3x300s imaging in r-band and 5x200s in z-band.
No new object is detected within the refined XRT error box (Evans et al. GCN
32330) in neither of the bands. The 3-signa detection limit in the r-band is
24.5 mag and 23.6 in z-band, calibrated with respect to Pan-STARRS field
stars. Our non detection is consistent with previous reports (Gendre et al.
GCN 32331, Lipunov et al. GCN 32332, Jiang et al. GCN 32335).
We do note that there is a faint source at the Northern edge of the error box,
at a distance of ~2.9��� from the centre of the XRT position, which is also
marginally detected in the Pan-STARRS images, and for which we measure
a magnitude of 24.1+/-0.3, with coordinates (J2000):
R.A.: 00:02:25.01
Dec.: -16:24:37.0
GCN Circular 32339
Subject
GRB 220706A, GROND observations
Date
2022-07-07T13:17:52Z (3 years ago)
From
Ana Nicuesa at TLS Tautenburg <ana@tls-tautenburg.de>
A. Nicuesa Guelbenzu, S. Klose (both TLS Tautenburg), and A. Rau (MPE
Garching) report:
We observed the field of GRB 220706A (D�Ai et al., GCN 32329) with
GROND mounted at the 2.2m MPG telescope at La Silla Observatory
(Chile).
Observations started at a midtime of 09:40 UT on July 07, 2022, about
17.5 hours after the GRB trigger and were on target for 20 minutes.
They were performed at an average seeing of 1.2 arcsec and at an
airmass close to 1.0.
Inside the enhanced Swift/XRT error circle (Goad et al., GCN 32333),
we do not detect an optical/NIR transient in any band down to the
following upper limits (AB mags; 3 sigma):
g' > 25.2,
r' > 24.9,
i' > 24.2,
J > 21.7,
H > 21.0,
K > 19.9.
Combining the GROND optical (g'r'i') and NIR (JHK) bands, no object is
detected inside the enhanced XRT error circle either.
Our measurements add to previousely reported results (Gendre et al.,
GCN 32331; Lipunov et al., GCN 32332; Jiang et al., GCN 32335; de
Ugarte-Postigo et al., GCN 32338).
The source at the northern border of the enhanced XRT error circle
reported by de Ugarte Postigo et al. (GCN 32338) is clearly detected
in our combined gri images. At present we cannot decide whether this
is a galaxy or not.
The given limits are derived based on calibrating the optical images
against the Pan-STARRS catalog and the JHK data against 2MASS stars.
We thank Sam Kim for excellent support and for performing the
observations.
GCN Circular 32340
Subject
GRB 220706A: Swift-XRT refined Analysis
Date
2022-07-07T13:36:08Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), A.P. Beardmore (U.
Leicester), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), T.
Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB), M.G. Bernardini
(INAF-OAB), B. Sbarufatti (PSU) and A. D'Ai report on behalf of the
Swift-XRT team:
We have analysed 6.6 ks of XRT data for GRB 220706A (D'Ai et al. GCN
Circ. 32329), from 87 s to 67.9 ks after the BAT trigger. The data
comprise 578 s in Windowed Timing (WT) mode (the first 8 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Goad et al.
(GCN Circ. 32330).
The late-time light curve (from T0+4.4 ks) can be modelled with a
power-law decay with a decay index of alpha=1.3 (+/-0.4).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.33 (+0.15, -0.14). The
best-fitting absorption column is 6.0 (+/-0.8) x 10^21 cm^-2, in
excess of the Galactic value of 2.4 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 3.5 x 10^-11 (7.6 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 6.0 (+/-0.8) x 10^21 cm^-2
Galactic foreground: 2.4 x 10^20 cm^-2
Excess significance: 12.4 sigma
Photon index: 2.33 (+0.15, -0.14)
If the light curve continues to decay with a power-law decay index of
1.3, the count rate at T+24 hours will be 0.016 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.6 x
10^-13 (1.2 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01114937.
This circular is an official product of the Swift-XRT team.
GCN Circular 32342
Subject
GRB 220706A: LCO Optical Upper Limits
Date
2022-07-08T01:42:44Z (3 years ago)
From
Robert Strausbaugh at U. of the Virgin Islands <robert.strausbaugh@uvi.edu>
R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (College of Marin) report on behalf of a larger collaboration:
We observed the Swift GRB 220706A (D'Ai et al., GCN 32329) field with the Siding Spring Observatory, Australia site, on July 6, from 18:15 to 18:52 (corresponding to 2.10 to 2.72 hours from the GRB trigger time) with the SDSS r and i filters.
We performed a series of 3x300s exposures in i and 2x300 and 1x135 r bands (the last r-band observation was interrupted). We do not detect an optical counterpart within the XRT enhanced error region (Goad et al., GCN 32333) in either band, consistent with other non-detections (Gendre et al., GCN 32331; Lipunov et al., GCN 32332; Jiang et al., GCN 32335; de Ugarte-Postigo et al., GCN 32338; Guelbenzu et al., GCN 32339).
The following upper limits are calculated using the PanSTARRS catalog as reference:
r>23.0
i>22.5
We also observed with the LCO 1-m Sinistro instrument at the Teide Observatory, on Tenerife, on July 7, from 04:25 to 04:52 UT (corresponding to 12.27 to 12.72 hours from the GRB trigger time) with the SDSS r and i filters.
We performed a series of 3x300s exposures in i and r bands.
The following upper limits are calculated using the PanSTARRS catalog as reference:
r>22.4
i>22.4
These magnitudes are not corrected for galactic extinction.
R.S. is funded by NSF AST grant #1831682
GCN Circular 32348
Subject
GRB 220706A: Swift-BAT refined analysis
Date
2022-07-08T14:07:29Z (3 years ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
M. Stamatikos (OSU), S. D. Barthelmy (GSFC), A. D'Ai (INAF-IASFPA),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC),
T. Sakamoto (AGU),
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 220706A (trigger #1114937)
(D'Ai, et al., GCN Circ. 32329). The BAT ground-calculated position is
RA, Dec = 0.577, -16.411 deg which is
RA(J2000) = 00h 02m 18.5s
Dec(J2000) = -16d 24' 38.8"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 73%.
The BAT mask-weighted light curve shows a bright peak starting from
T-3 s to T+30 s. The weak emission is evident in the 10-s binned
light curve starting from T-80 s to T+70 s. T90 (15-350 keV) is
86.9 +- 18.0 sec (estimated error including systematics).
The time-averaged spectrum from T-71.84 to T+36.15 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.75 +- 0.17. The fluence in the 15-150 keV band is 1.4 +- 0.1 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+3.72 sec in the 15-150 keV band
is 0.9 +- 0.2 ph/cm2/sec. 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/1114937/BA/
GCN Circular 32351
Subject
GRB 220706A: Swift/UVOT Upper Limits
Date
2022-07-08T20:06:11Z (3 years ago)
From
Sam LaPorte at PSU <sjl5346@psu.edu>
GRB 220706A: Swift/UVOT Upper Limits
S. J. LaPorte (PSU) and A. D'Ai (INAF-IASFPA)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 220706A
107 s after the BAT trigger (D'Ai et al., GCN Circ. 32329).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 32333)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 107 257 147 >20.5
u_FC 320 570 246 >20.0
white 107 1025 334 >20.5
b 751 771 19 >18.5
u 320 570 246 >20.0
w1 701 720 19 >17.8
m2 849 869 19 >18.6
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.025 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 32353
Subject
GRB 220706A : NICER detection of re-brightening 1 day after the Swift trigger
Date
2022-07-09T00:07:58Z (3 years ago)
From
Motoko Serino at Aoyama Gakuin U. <serino@phys.aoyama.ac.jp>
W. Iwakiri (Chuo U.), M. Shidatsu (Ehime.U), M. Serino (AGU), K. C. Gendreau, Z. Arzoumanian (NASA/GSFC),
T. Enoto, T. Mihara (RIKEN)
We report on initial NICER observations of GRB 220706A (GCN #32329) carried out on 2022 July 7.
The observations were carried out in two parts. The first epoch began at 01:36 UT, approximately a half-day
after the Swift/BAT trigger (GCN #32329), and ended at 03:34 UT, with ~1.5 ksec of exposure across two
successive orbits of the International Space Station (ISS). The lightcurve shows a slow decay:
the NICER-measured X-ray flux decreased from 8 x 10-13 to 6 x 10-13 erg/cm2/s in the 0.3-10 keV band.
The emission overall was soft, with hardness ratio of 0.1 between the 0.3-2.0 and 2.0-10.0 keV bands.
The second epoch was from 17:08 to 22:09 UT (~1 day after the Swift/BAT detection), with 3.4 ksec exposure
in total. We found re-brightening of the afterglow: the NICER average flux during the second epoch
was 6.5 x 10-12 erg/cm2/s in 0.3-10 keV, with a hardness ratio of 0.6. The result suggests that the spectrum
has significantly hardened compared with the first-epoch results, unlike typical GRBs.
NICER will continue to monitor this source. Multi-wavelength followup observations are strongly encouraged.
Note: Because the nature of the source is unknown, this message is cross-posted to ATel and GCN.