GRB 220325A
GCN Circular 31787
Subject
GRB 220325A: Swift detection of a burst
Date
2022-03-25T17:27:31Z (3 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
M. Ferro (INAF-OAB), M. G. Bernardini (INAF-OAB),
R. Brivio (INAF-OAB), P. D'Avanzo (INAF-OAB), J.D. Gropp (PSU),
J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL), S. Laha (GSFC/UMBC),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL), T. M. Parsotan (GSFC/UMBC/CRESSTII),
T. Sbarrato (INAF-OAB), B. Sbarufatti (PSU) and M. H. Siegel (PSU)
report on behalf of the Neil Gehrels Swift Observatory Team:
At 17:16:23 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 220325A (trigger=1099310). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 269.485, -7.031 which is
RA(J2000) = 17h 57m 56s
Dec(J2000) = -07d 01' 50"
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 ~8 sec. The peak count rate
was ~2000 counts/sec (15-350 keV), at ~1 sec after the trigger.
The XRT began observing the field at 17:18:13.2 UT, 110.2 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source located at RA, Dec 269.48760, -7.03776 which
is equivalent to:
RA(J2000) = 17h 57m 57.02s
Dec(J2000) = -07d 02' 15.9"
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This
location is 26 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. No
spectrum from the promptly downlinked event data is yet available to
determine the column density.
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 114 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
0.915.
Burst Advocate for this burst is M. Ferro (matteo.ferro 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 31789
Subject
GRB 220325A: MASTER Global Robotic Net optical observations
Date
2022-03-25T20:18:18Z (3 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V.Lipunov, D.Vlasenko, A.Kuznetsov, O.Gress, E.Gorbovskoy, N.Tyurina, P.Balanutsa, K.Zhirkov, A.Chasovnikov,
G.Antipov, V.Senik, D.Kuvshinov, V.Topolev,Ya.Kechin, Yu.Tselik (Lomonosov Moscow State University, SAI, Physics Department),
C.Francile, R. Podesta, C.Lopez, F. Podesta (Observatorio Astronomico Felix Aguilar OAFA),
D.A.H.Buckley (SAAO),
R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.Corella,
L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory),
N.M.Budnev (ISU,API),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov (Blagoveschensk Educational State University)
MASTER-Amur robotic telescope (Global MASTER-Net: http://observ.pereplet.ru,Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)
was pointed to the SWIFT GRB 220325A ( M. Ferro et al., GCN 31787) errorbox
3287 sec after notice time (3306 sec after trigger time)
at 2022-03-25 18:11:29 UT between rain with snow with upper limit up to 15.1 mag.
The observations started at zenith distance = 69 deg. The sun altitude was -28.4 deg.
The galactic latitude b = 8 deg., longitude l = 21 deg.
Real time updated cover map is available:
https://master.sai.msu.ru/site/master2/observ.php?id=1921440
The observation and reduction will continue.
The message may be cited.
GCN Circular 31790
Subject
GRB 220325A: Enhanced Swift-XRT position
Date
2022-03-25T20:47:24Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1551 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 220325A, 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 = 269.48753, -7.03592 which is equivalent
to:
RA (J2000): 17h 57m 57.01s
Dec (J2000): -07d 02' 09.3"
with an uncertainty of 2.4 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 31791
Subject
Fermi GBM Sub-Threshold Detection of GRB 220325A
Date
2022-03-26T03:41:37Z (3 years ago)
From
Joshua Wood at MSFC/Fermi-GBM <joshua.r.wood@nasa.gov>
J. Wood (NASA/MSFC) reports on behalf of the Fermi-GBM Team:
There was no Fermi-GBM onboard trigger around the time of GRB 220325A,
which was detected by Swift-BAT at 17:16:23 UT on 25 March, 2022 (Ferro
et al. GCN 31787).
An automated, blind search for short gamma-ray bursts below the onboard
triggering threshold in Fermi-GBM identified GRB 220325A with medium
reliability [1], with a localization consistent with the Swift-BAT
location at the ~2 sigma level, and a discovery timescale of 2.751 s.
The start time of the GBM sub-threshold detection coincides with the time
of the peak photon flux observed by Swift-BAT.
The GBM targeted search [2], the most sensitive, coherent search for
GRB-like signals also identified a transient most significantly on the 2.048 s
timescale, with a location consistent with the Swift-BAT event at
the ~2 sigma level and a signal-to-noise ratio of 12.3,
using the standard search protocol.
The GBM targeted search event was found with the highest
significance with a "soft" spectrum (Band function with
Epeak = 70 keV, alpha = -1.9, beta = -3.7) for a GRB.
This analysis is preliminary.
[1] https://gcn.gsfc.nasa.gov/notices_gbm_sub/669921389.fermi
[2] Goldstein et al. 2019 arXiv:1903.12597
GCN Circular 31793
Subject
GRB 220325A: 1.3m DFOT Optical upper limit
Date
2022-03-26T09:35:16Z (3 years ago)
From
Rahul Gupta at ARIES, India <rahulbhu.c157@gmail.com>
Rahul Gupta, Amit Ror, Amit Kumar, Dimple, Ankur Ghosh, Amar Aryan, Krishan
Chand, S. B. Pandey, and Kuntal Misra (ARIES) report:
We observed the Swift-BAT and Fermi-GBM Sub-Threshold detected GRB 220325A (
Ferro et al., GCN 31787; Wood, GCN 31791) with 1.3m Devasthal Fast
Optical Telescope
(DFOT) located at Devasthal observatory of Aryabhatta Research Institute of
Observational Sciences (ARIES), India. The observations were started on
2022-03-25 at ~ 22:15 UT, i.e., ~ 5 hours after the BAT trigger. We have
taken multiple frames having an exposure time of 300 sec in the R filter.
We stacked the images after the alignment. We did not detect any new
optical source
within the Swift XRT uncertainty circle (Osborne et al., GCN 31790) in our
stacked image.
We obtain the following 3-sigma upper limit in the stacked image.
Date Start_UT T_start-T0 (hour) Filter Exp time (sec) Limiting magnitude
====================================================
2022-03-25 22:15 ~5 R 300*20 > 21.7
The magnitude is not corrected for the Galactic extinction in the direction
of the burst. Photometric calibration is performed using the standard stars
from the USNO-B1.0 catalog.
This circular may be cited.
GCN Circular 31794
Subject
GRB 220325A: Swift-XRT refined Analysis
Date
2022-03-26T10:49:46Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U.
Leicester), M.G. Bernardini (INAF-OAB), E. Ambrosi (INAF-IASFPA) , M.
Capalbi (INAF-IASFPA), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto),
B. Sbarufatti (PSU) and M. Ferro report on behalf of the Swift-XRT
team:
We have analysed 6.7 ks of XRT data for GRB 220325A (Ferro et al. GCN
Circ. 31787), from 95 s to 35.5 ks after the BAT trigger. The data
comprise 8 s in Windowed Timing (WT) mode (taken while Swift was
slewing), with the remainder in Photon Counting (PC) mode. The enhanced
XRT position for this burst was given by Osborne et al. (GCN Circ.
31790).
The light curve can be modelled with a power-law decay with a decay
index of alpha=0.67 (+/-0.06).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.51 (+0.28, -0.16). The
best-fitting absorption column is 3.96 (+1.97, -0.09) x 10^21 cm^-2,
consistent with the Galactic value of 3.9 x 10^21 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum is 5.2 x 10^-11 (6.5 x
10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 3.96 (+1.97, -0.09) x 10^21 cm^-2
Galactic foreground: 3.9 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index: 1.51 (+0.28, -0.16)
If the light curve continues to decay with a power-law decay index of
0.67, the count rate at T+24 hours will be 7.6 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.0 x
10^-13 (5.0 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01099310.
This circular is an official product of the Swift-XRT team.
GCN Circular 31795
Subject
GRB 220325A: LCO Optical Upper Limits
Date
2022-03-26T13:24:25Z (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 Swift GRB 220325A (Ferro et al., GCN 31787) with the LCO 1-m Sinistro instrument at the McDonald Observatory, Texas, USA site, on March 26, from 09:25 to 09:53 UT (corresponding to 16.15 to 16.62 hours from the GRB trigger time) with the Bessel R and I filters.
We performed a series of 3x300s exposures in I and R bands. We do not detect an optical counterpart within the XRT enhanced error region (Osborne et al., GCN 31790) in either band, consistent with other non-detections (Lipunov et al., GCN 31773; Gupta et al., GCN 31793). The following upper limits are calculated using the USNO-B.1 catalog as reference:
R>21.08
I>20.14
These magnitudes are not corrected for galactic extinction.
R.S. is funded by NSF AST grant #1831682
GCN Circular 31797
Subject
GRB 220325A: Tautenburg observations
Date
2022-03-26T20:47:50Z (3 years ago)
From
Ana Nicuesa at TLS Tautenburg <ana@tls-tautenburg.de>
A. Nicuesa Guelbenzu, S. Klose, B. Stecklum, S. Melnikov, and
U. Laux (all Tautenburg) report:
We observed the field of GRB 220325A (Ferro et al. GCN 31787) with the
Tautenburg 1.34m Schmidt telescope equipped with the TAUKAM 6k x 6k
CCD camera. Observations consisted of 3x3 min exposures using the
Sloan r, i, and z-band filter. The airmass was 2.1, the seeing
relatively poor (3 arcsec).
Inside the enhanced XRT error circle (Osborne et al., GCN 31790) we do not
find any source down to the following magnitudes:
r > 20.7 mag (AB, 3 sigma), mean time: 2022-03-26, 03:05:34 UT,
i > 20.6 mag (AB, 3 sigma), mean time: 2022-03-26, 03:16:22 UT,
z > 19.7 mag (AB, 3 sigma). mean time: 2022-03-26, 03:27:10 UT,
calibrated against the Pan-STARRS catalog.
GCN Circular 31799
Subject
GRB 220325A: Swift-BAT refined analysis
Date
2022-03-28T15:14:06Z (3 years ago)
From
Sibasish Laha at GSFC <sibasish.laha@nasa.gov>
S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF), A. Y. Lien (U Tampa)
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU),
M. Stamatikos (OSU) (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 220325A (trigger #1099310)
(Ferro et al., GCN Circ. 31787). The BAT ground-calculated position is
RA, Dec = 269.469, -7.055 deg which is
RA(J2000) = 17h 57m 52.7s
Dec(J2000) = -07d 03' 18.4"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 52%.
The BAT light curve showed a complex
structure with a duration of about 6 sec.
T90 (15-350 keV) is 3.50 +- 0.56 sec (estimated error including systematics).
The time-averaged spectrum from T-0.97 to T+3.02 sec is best fit by a power law
with an exponential cutoff. This fit gives a photon index 0.69 +- 1.13,
and Epeak of 39.3 +- 8.9 keV (chi squared 63.15 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 2.9 +- 0.4 x 10^-07 erg/cm2
and the 1-sec peak flux measured from T+0.53 sec in the 15-150 keV band is
2.0 +- 0.3 ph/cm2/sec. A fit to a simple power law gives a photon index
of 2.06 +- 0.17 (chi squared 69.80 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/1099310/BA/
GCN Circular 31801
Subject
GRB 220325A: Swift/UVOT Upper Limits
Date
2022-03-28T16:02:38Z (3 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and M. Ferro (INAF-OAB)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 220325A
114 s after the BAT trigger (Ferro et al., GCN Circ. 31787).
No optical afterglow consistent with the XRT position
(Osborne et al. GCN Circ. 31790)
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 114 264 147 >20.8
u_FC 326 576 246 >20.1
white 114 5035 488 >21.0
v 657 1234 78 >18.7
b 582 4893 255 >20.1
u 326 4688 481 >20.3
w1 707 726 19 >17.9
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.915 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 31804
Subject
GRB 220325A: GRANDMA observations
Date
2022-03-29T18:08:27Z (3 years ago)
From
Sarah Antier at OCA <sarah.antier@oca.eu>
C. Andrade, M. Coughlin (UNM), K. Noysena (NARIT), W. Kiendrebeogo (UJS),
I. Tosta e Melo (INFN-LNS), X. F. Wang (TSU/BJP), F. Navarete (NOIRLab/SOAR)
J. Zhu (BJP), L. Wang (XAO), A. Iskandar (XAO), X. Zeng (XAO), L. Abe,
Ph. Bendjoya, J.-P. Rivet (Lagrange/OCA), D. Vernet (Galilee/OCA),
S. Antier, A. de Ugarte Postigo (Artemis/OCA), A. M. Fouad, A. Taky,
A. Shokry, I. Elhousiny, A. Eid, M. Farouk (NRIAG), P.A. Duverne (IJCLAB)
report on behalf of the GRANDMA collaboration:
The GRANDMA telescope network responded to the alert of GRB 220325A
(Palmer et al. GCN 31787). The first observations started 4.28 h after
the BAT trigger time.
No new object was detected within the XRT enhanced error region (Evans et
al. GCN 31794). In the following table we report the preliminary photometry
of our observations. Upper limits are reported at the 3-sigma limit, in the
AB system.
T-T0 (hr)| MJD������ | Observatory| Exposure| Filter���� | Upp.Lim. (AB)
_____________________________________________________________________
04.28 |59663.89971| SNOVA���������� | 9x300s�� | Bessel R | 20.1
04.44 |59663.90475| NOWT������������ | 11x180s | Bessel R | 19.7
08.11 |59664.05765| KAO�������������� | 22x50s�� |�� SDSS i�� | 21.2
10.14 |59664.14304| C2PU������������ | 16x240s |�� SDSS r�� | 20.8
These limits are consistent with the non-detections previously reported
(Gupta et al. GCN 31793, Strausbaugh et al. GCN 31795, Nicuesa Guelbenzu et
al. GCN 31797).
The photometry of NOWT and SNOVA was performed using field stars from the
APASS catalog. The KAO and C2PU image have been processed using field stars
from the PanSTARRS-DR1 catalog and with the MUPHOTEN pipeline (Duverne et
al. 2021).
The magnitudes are not corrected for the Galactic extinction in the
direction of the burst.
GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr)
devoted to the observation of transients in the context of multi-messenger
astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is
the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/).