GRB 220701A
GCN Circular 32306
Subject
GRB 220701A: Swift detection of a burst
Date
2022-07-01T05:12:33Z (3 years ago)
From
Kim Page at U.of Leicester <kimlpage1978@gmail.com>
P. A. Evans (U Leicester), S. Dichiara (PSU), H. A. Krimm (NSF),
K. L. Page (U Leicester), T. M. Parsotan (GSFC/UMBC/CRESSTII) and
M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 04:52:58 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 220701A (trigger=1114034). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 242.478, +55.420 which is
RA(J2000) = 16h 09m 55s
Dec(J2000) = +55d 25' 14"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a double-peaked
structure with a duration of about 16 sec. The peak count rate
was ~1000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 04:56:06.0 UT, 187.9 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 242.50589, 55.40679 which is equivalent
to:
RA(J2000) = 16h 10m 01.41s
Dec(J2000) = +55d 24' 24.4"
with an uncertainty of 4.2 arcseconds (radius, 90% containment). This
location is 74 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. 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 1.03
x 10^20 cm^-2 (Willingale et al. 2013).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 175 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 85% 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
0.008.
Burst Advocate for this burst is P. A. Evans (pae9 AT leicester.ac.uk).
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 32308
Subject
GRB 220701A: Enhanced Swift-XRT position
Date
2022-07-01T06:34:49Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester)
report on behalf of the Swift-XRT team.
Using 962 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 220701A, 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 = 242.50501, +55.40820 which is equivalent
to:
RA (J2000): 16h 10m 1.20s
Dec (J2000): +55d 24' 29.5"
with an uncertainty of 2.6 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 32309
Subject
GRB 220701A: Lowell Discovery Telescope Optical Observations
Date
2022-07-01T09:46:37Z (3 years ago)
From
Brendan O'Connor at UMD <oconnorb@umd.edu>
B. O'Connor (UMD, GWU), S.B. Cenko (UMD, NASA-GSFC), E. Troja (UTV),
S. Dichiara (PSU), A. Kutyrev (UMD, NASA-GSFC), S. Veilleux (UMD):
We observed GRB 220701A (Evans et al. GCN 32306) with the Large
Monolithic Imager (LMI) on the 4.3-m Lowell Discovery Telescope (LDT).
Observations began on July 1, 2022 at 08:01:14 UT in r-band (~3.1 hr
after the GRB) for a total exposure of 1000 s at airmass 1.3 and
seeing 1.2". Within the XRT enhanced position (Evans et al. GCN 32308)
we do not detect a source to depth r > 24.3 AB mag.
Magnitudes are calibrated against the SDSS catalog and are not corrected
for Galactic extinction.
We thank the staff of the Lowell Discovery Telescope for assistance
with these observations.
GCN Circular 32310
Subject
GRB 220701A: Swift/UVOT Upper Limits
Date
2022-07-01T11:27:13Z (3 years ago)
From
Samantha Oates at MSSL <samantha.oates@alumni.ucl.ac.uk>
S. R. Oates (U. Birmingham) and P. A. Evans (U. Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 220701A
175 s after the BAT trigger (Evans et al., GCN Circ. 32306).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 32308)
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 175 325 147 >21.0
u_FC 333 583 246 >20.2
white 175 1884 424 >21.6
v 665 1758 136 >19.2
b 589 1858 136 >20.2
u 333 1833 363 >20.5
w1 714 1808 117 >19.4
w2 640 1906 55 >18.5
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.008 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 32311
Subject
GRB 220701A: BOOTES-5/JGT early optical upper limit
Date
2022-07-01T14:37:07Z (3 years ago)
From
Youdong HU at IAA-CSIC <huyoudong072@hotmail.com>
Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado, I. Perez-Garcia, M.D. Caballero-Garcia, R. Sanchez-Ramirez (IAA-CSIC), D. Hiriart and W. H. Lee (UNAM), C. J. Perez del Pulgar and I. Carrasco (UMA), I. H. Park (SKKU) on behalf of a larger collaboration, report:
Following the detection of GRB 220701A by Swift (Evans et al. GCNC 32306), the BOOTES-5/JGT 0.6m robotic telescope at Observatorio Astronomico Nacional in San Pedro Martir (Mexico) observed the GRB location starting on Jul 01, 04:55:30 UT (~152 s after trigger). In the early co-added image (20 x 10 s exposures in the clear filter), no optical afterglow is detected within the Swift/XRT error region (Evans et al. GCNC 32306, GCNC 32308) down to 20.4 mag. This non-detection is consistent with those results from KAIT (Zheng et al. GCNC 32307), LDT (O'Connor et al. GCNC 32309) and UVOT (Oates et al. GCNC 32310).
We thank the staff at Observatorio Astronomico Nacional in San Pedro Martir for their excellent support.
GCN Circular 32313
Subject
GRB 220701A: LCO Optical Upper Limits
Date
2022-07-02T01:37:45Z (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 220701A (Evans et al., GCN 32306) field with the LCO 1-m Sinistro instrument at the Teide Observatory, on Tenerife, on July 1, from 21:07 to 21:34 UT (corresponding to 16.25 to 16.70 hours from the GRB trigger time) with the SDSS r and i filters.
We performed a series of 3x300s exposures in r and i bands. We do not detect an optical counterpart within the XRT enhanced error region (Evans et al., GCN 32308) in either band, consistent with other non-detections (O'Connor et al., GCN 32309; Oates et al., GCN 32310; Hu et al., GCN 32311). The following upper limits are calculated using the PanSTARRS catalog as reference:
r>22.9
i>21.9
These magnitudes are not corrected for galactic extinction.
R.S. is funded by NSF AST grant #1831682
GCN Circular 32314
Subject
GRB 220701A: Swift-XRT refined Analysis
Date
2022-07-02T02:45:03Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
J. D. Gropp (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), K.L.
Page (U. Leicester), A.P. Beardmore (U. Leicester), A. Melandri
(INAF-OAB), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB) and P.A.
Evans report on behalf of the Swift-XRT team:
We have analysed 6.2 ks of XRT data for GRB 220701A (Evans et al. GCN
Circ. 32306), from 178 s to 52.7 ks after the BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Evans et al. (GCN Circ. 32308).
The light curve can be modelled with a power-law decay with a decay
index of alpha=1.03 (+0.15, -0.12).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.3 (+0.7, -0.6). The
best-fitting absorption column is 1.2 (+0.7, -0.5) x 10^22 cm^-2, in
excess of the Galactic value of 1.0 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 4.4 x 10^-11 (1.1 x 10^-10) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.2 (+0.7, -0.5) x 10^22 cm^-2
Galactic foreground: 1.0 x 10^20 cm^-2
Excess significance: 4.0 sigma
Photon index: 2.3 (+0.7, -0.6)
If the light curve continues to decay with a power-law decay index of
1.03, the count rate at T+24 hours will be 5.6 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.4 x
10^-14 (6.3 x 10^-14) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01114034.
This circular is an official product of the Swift-XRT team.
GCN Circular 32315
Subject
GRB 220701A: Keck/LRIS Optical Upper Limit
Date
2022-07-02T10:47:23Z (3 years ago)
From
Weikang Zheng at UC Berkeley <weikang@berkeley.edu>
WeiKang Zheng, Yi Yang, Thomas G. Brink and Alexei V. Filippenko
(UC Berkeley) report on behalf of the KAIT GRB team:
We observed the field of GRB 200701A (Evans al., GCN 32306) with the
Low Resolution Imaging Spectrometer (LRIS) mounted on the 10-m Keck I
telescope, started at 10:41 UT on July 1st (5.82 hours after the burst).
We obtained 5x180s exposure in g and RG850 (close to z) filter
simultaneously,
under the averaged seeing ~1.2". We do not detect any optical afterglow
candidate within the enhanced XRT position error circle (Evans al., GCN
32308)
with the following upper limit, calibrated to the Pan-STARRS1 catalog in
g and z filter:
g > 24.5
z > 22.8
Our result is consistent with other non-detections (Zheng et al. GCNC 32307;
O'Connor et al., GCN 32309; Oates et al., GCN 32310; Hu et al., GCN 32311,
Strausbaugh et al., GCN 32313).
GCN Circular 32317
Subject
GRB 220701A: AbAO optical upper limit
Date
2022-07-02T14:30:24Z (3 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
S. Belkin (IKI), N. Pankov (IKI), A. Pozanenko (IKI), R. Ya. Inasaridze
(AbAO), V. R. Ayvazian (AbAO), D. Datashvili (AbAO), G. V. Kapanadze
(AbAO) report on behalf of GRB IKI FuN
We observed the field of GRB 220701A detected by Swift (Evans et al.,
GCN 32306;) with AS-32 telescope of Abastumani Observatory (AbAO)
starting on 2022-07-01 (UT) 17:54:12. We do not detect any optical
sources within enhanced XRT position (Evans et al., GCN 32308). This
upper limit is consistent with earlier and later non detection
(O'Connor et al. GCN 32309; Oates et al. GCN 32310; Hu et al. GCN
32311; Strausbaugh et al. GCN 32313; Zheng et al. GCN 32315).
Preliminary upper limit of a stacked image is following:
Date, UT start, t-T0, Exp., Filter, OT, Err, UL(3 sigma)
(mid, days)
2022-07-01 17:54:12 0.55016 22*60 R n/d n/d 21.0
The photometry is based on nearby USNO-B1.0 stars, R2 magnitude
RA DEC R2
16:10:21.85344 +55:26:18.9924 15.49
16:10:42.83688 +55:25:01.9920 17.38
16:10:59.99544 +55:21:15.1020 16.08
16:10:33.30600 +55:17:14.3520 16.76
GCN Circular 32318
Subject
GRB 220701A: COATLI Optical Upper Limit
Date
2022-07-02T17:50:14Z (3 years ago)
From
Alan M Watson at UNAM <alan@astro.unam.mx>
Alan M. Watson (UNAM), Margarita Pereyra (UNAM), Nat Butler (ASU), Rosa L.
Becerra (UNAM), Oc��lotl L��pez (UNAM), Diego Gonz��lez (UNAM), Alexander Kutyrev
(GSFC), William H. Lee (UNAM), Eleonora Troja (GSFC) and Tzveti Dimitrova (ASU)
report:
We observed the field of GRB 220701A (Evans et al., GCN Circ. 32306) with the
COATLI 50-cm telescope and interim imager at the Observatorio Astron��mico
Nacional on the Sierra de San Pedro M��rtir (http://coatli.astroscu.unam.mx) from
2022-07-02 03:45 UTC to 11:21 UTC (22.81 to 30.41 hours after the trigger),
obtaining a total of 21405 seconds of exposure in the r filter.
We do not detect any uncataloged sources in the XRT error region (Evans et al.,
GCN Circ. 32306) to a 3-sigma limit of r = 23.7.
Our photometry is calibrated against the Pan-STARRS1 catalog, are on an
approximate AB system, and are not corrected for Galactic extinction in the
direction of the GRB.
We thank the COATLI technical team and the staff of the Observatorio Astron��mico
Nacional.
GCN Circular 32320
Subject
GRB 220701A: MITSuME Akeno optical upper limits
Date
2022-07-04T06:38:32Z (3 years ago)
From
Yutaka Takamatsu at Tokyotech <takamatsu@hp.phys.titech.ac.jp>
Y. Takamatsu, N. Ito, M. Niwano, Y. Imai, S. Sato, M. Tateda, N.
Higuchi, T. Hattori, R. Hosokawa, K. L. Murata, M. Sasada, Y. Yatsu,
and N. Kawai (Tokyo Tech) report on behalf of the MITSuME
collaboration:
We observed the field of GRB 220701A (P. A. Evans et al. GCN Circular
#32306 & #32308, B. O'Connor et al. GCN Circular #32309, S. R. Oates
et al. GCN Circular #32310, Y.-D. Hu et al. GCN Circular #32311, R.
Strausbaugh et al. GCN Circular #32313, J. D. Gropp et al. GCN
Circular #32314, WeiKang Zheng et al. GCN Circular #32315, S. Belkin
et al. GCN Circular #32317, Alan M. Watson et al. GCN Circular #32318)
with the optical three color (g', Rc, and Ic) CCD cameras attached to
the MITSuME 50 cm telescope Akeno.
The observation with a series of 60 sec exposures started at
2022-07-01 19:37:09 UT (884 minutes after the Swift/BAT trigger). We
stacked the images with good conditions. We did not detect any
uncatalogued sources within the enhanced Swift/BAT error region (Evans
et al. GCN Circular #32306). We obtained the 5-sigma limits of the
stacked images as follows.
T0+[days] | MID-UT | T-EXP[sec] | 5-sigma limits
------------------------------------------------------------------------------------------------
0.6 | 2022-07-01 14:31:19 | 9060 | g'>19.4, Rc>20.1, Ic>20.9
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used PS1 catalog for flux calibration. The magnitudes are expressed
in the AB system. The images were processed in real-time through the
MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ, Vol.73,
Issue 1, Pages 4-24; https://github.com/MNiwano/Eclaire).
GCN Circular 32325
Subject
GRB220701A: VIRT Optical Upper Limit
Date
2022-07-05T17:51:12Z (3 years ago)
From
Priyadarshini Gokuldass at U. of the Virgin Islands <priyadass.94@gmail.com>
P. Gokuldass (Florida Institute of Technology), N. Orange (OrangeWave
Innovative Science, LLC), K. Noonan (UVI), R. Querrard (UVI), K. Smith
(UVI), D. Morris (UVI) report:
We observed the field of GRB220701A (Evans et al., GCN 32306) with the 0.5m
Virgin Island Robotic Telescope (VIRT) at the University of the Virgin
Islands' Etelman Observatory on 07-01-2022 starting at 05:16:18.64 UT (T+24
min). We performed a series of exposures in the R filter with a total
exposure of 3300 s. The weather conditions were partly cloudy during the
hours of observation with an average airmass of 2.
We detect no new source within the enhanced XRT position error circle
(Evans et al., 32308), consistent with other non-detections (Zheng et al.
GCN 32307; O'Connor et al. GCN 32309; Oates et al. GCN 32310; Hu et al.
GCN 32311; Strausbaugh et al. GCN 32313; Belkin et al. GCN 32317) and
report the following 5-sigma upper limit:
T_mid ||Exposure ||Filter ||Limit
T+ 1.5 hrs ||3300s ||R ||>19.8
The limit is estimated from comparison to nearby USNO B1 stars and is not
corrected for Galactic extinction. The VIRT is still in the commissioning
phase.
We acknowledge financial support from NASA MUREP MIRO award 80NSSC21M0001, NASA
EPSCoR award 80NSSC19M0060, and NSF EiR award 1901296.This message can be
cited.
GCN Circular 32328
Subject
GRB 220701A: Swift-BAT refined analysis
Date
2022-07-06T13:57:34Z (3 years ago)
From
Hans Krimm at NSF/NASA-GSFC <hkrimm@nsf.gov>
T. Sakamoto (AGU), S. D. Barthelmy (GSFC), P. A. Evans (U Leicester),
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),
M. Stamatikos (OSU)(i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 220701A (trigger #1114034)
(Evans, et al., GCN Circ. 32306). The BAT ground-calculated position is
RA, Dec = 242.474, 55.436 deg which is
RA(J2000) = 16h 09m 53.7s
Dec(J2000) = +55d 26' 08.9"
with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 56%.
The BAT mask-weighted light curve shows a fairly weak peak extending from
Roughly T-2 to T+8 seconds. T90 (15-350 keV) is 5.77 +- 1.13 sec (estimated
error including systematics).
The time-averaged spectrum from T-1.40 to T+4.83 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.37 +- 0.34. The fluence in the 15-150 keV band is 1.8 +- 0.4 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+3.65 sec in the 15-150 keV band
is 0.7 +- 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/1114034/BA/