Gamma-ray Burst 220701A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 01 Jul 22 04:54:16 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1114034,   Seg_Num: 0
GRB_RA:          242.478d {+16h 09m 55s} (J2000),
                 242.605d {+16h 10m 25s} (current),
                 242.196d {+16h 08m 47s} (1950)
GRB_DEC:         +55.420d {+55d 25' 14"} (J2000),
                 +55.363d {+55d 21' 46"} (current),
                 +55.550d {+55d 32' 59"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       44370 [cnts]    Image_Peak=576 [image_cnts]
TRIGGER_DUR:     16.384 [sec] 
TRIGGER_INDEX:   479     E_range: 25-100 keV
BKG_INTEN:       164007 [cnts]
BKG_TIME:        17474.58 SOD {04:51:14.58} UT
BKG_DUR:         64 [sec]
GRB_DATE:        19761 TJD;   182 DOY;   22/07/01
GRB_TIME:        17578.07 SOD {04:52:58.07} UT
GRB_PHI:           1.74 [deg]
GRB_THETA:        38.47 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     9.16 [sigma]
IMAGE_SIGNIF:    7.65 [sigma]
MERIT_PARAMS:     +1  +0  +0  +4  +2  -2  +0  +0  +8  +0 
SUN_POSTN:       100.19d {+06h 40m 46s}  +23.10d {+23d 06' 18"}
SUN_DIST:         95.24 [deg]   Sun_angle= -9.5 [hr] (East of Sun)
MOON_POSTN:      125.63d {+08h 22m 32s}  +24.37d {+24d 22' 09"}
MOON_DIST:        83.99 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:       85.51, 44.64 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      207.11, 72.86 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This Notice was delayed by more than 60 sec past the end of the trigger integration interval;  
COMMENTS:        probably due to it occurring during a Malindi downlink session.  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 216.49,-1.51 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 01 Jul 22 04:57:00 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1114034,   Seg_Num: 0
GRB_RA:          242.478d {+16h 09m 55s} (J2000),
                 242.605d {+16h 10m 25s} (current),
                 242.196d {+16h 08m 47s} (1950)
GRB_DEC:         +55.420d {+55d 25' 14"} (J2000),
                 +55.363d {+55d 21' 46"} (current),
                 +55.550d {+55d 32' 59"} (1950)
GRB_DATE:        19761 TJD;   182 DOY;   22/07/01
GRB_TIME:        17578.07 SOD {04:52:58.07} UT
TRIGGER_INDEX:   479
GRB_PHI:           1.74 [deg]
GRB_THETA:        38.47 [deg]
DELTA_TIME:      52.00 [sec]
TRIGGER_DUR:     16.384 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     9.16 [sigma]
IMAGE_SIGNIF:    7.65 [sigma]
LC_URL:          sw01114034000msb.lc
SUN_POSTN:       100.19d {+06h 40m 46s}  +23.10d {+23d 06' 17"}
SUN_DIST:         95.24 [deg]   Sun_angle= -9.5 [hr] (East of Sun)
MOON_POSTN:      125.66d {+08h 22m 38s}  +24.36d {+24d 21' 53"}
MOON_DIST:        83.98 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:       85.51, 44.64 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      207.11, 72.86 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.  
COMMENTS:           
COMMENTS:        The next comments were copied from the BAT_POS Notice:  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 216.49,-1.51 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 01 Jul 22 04:58:42 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1114034,   Seg_Num: 0
POINT_RA:        242.450d {+16h 09m 48s} (J2000)
POINT_DEC:       +55.425d {+55d 25' 32"} (J2000)
POINT_ROLL:      325.607d
IMG_START_DATE:  19761 TJD;   182 DOY;   22/07/01
IMG_START_TIME:  17753.15 SOD {04:55:53.15} UT,   175.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.243
N_STARS:         48
X_OFFSET:        429 [pixels]
Y_OFFSET:        672 [pixels]
X_MAX:           1388 [pixels]
Y_MAX:           1631 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw01114034000msufc0175.fits
SUN_POSTN:       100.19d {+06h 40m 46s}  +23.10d {+23d 06' 17"}
SUN_DIST:         95.23 [deg]   Sun_angle= -9.5 [hr] (East of Sun)
MOON_POSTN:      125.67d {+08h 22m 42s}  +24.36d {+24d 21' 43"}
MOON_DIST:        83.96 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:       85.53, 44.66 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      207.06, 72.86 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 01 Jul 22 04:58:57 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1114034,   Seg_Num: 0
POINT_RA:        242.450d {+16h 09m 48s} (J2000)
POINT_DEC:       +55.425d {+55d 25' 32"} (J2000)
POINT_ROLL:      325.607d
IMG_START_DATE:  19761 TJD;   182 DOY;   22/07/01
IMG_START_TIME:  17753.15 SOD {04:55:53.15} UT,   175.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.243
N_STARS:         48
X_OFFSET:        429 [pixels]
Y_OFFSET:        672 [pixels]
X_MAX:           1388 [pixels]
Y_MAX:           1631 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw01114034000msufc0175.fits
SUN_POSTN:       100.19d {+06h 40m 47s}  +23.10d {+23d 06' 17"}
SUN_DIST:         95.23 [deg]   Sun_angle= -9.5 [hr] (East of Sun)
MOON_POSTN:      125.68d {+08h 22m 42s}  +24.36d {+24d 21' 41"}
MOON_DIST:        83.96 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:       85.53, 44.66 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      207.06, 72.86 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 01 Jul 22 05:00:17 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1114034,   Seg_Num: 0
POINT_RA:        242.450d {+16h 09m 48s} (J2000)
POINT_DEC:       +55.425d {+55d 25' 32"} (J2000)
ROLL:            325.607d
IMG_START_DATE:  19761 TJD;   182 DOY;   22/07/01
IMG_START_TIME:  17753.15 SOD {04:55:53.15} UT,   175.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     678344182
X_OFFSET:        748 [pixels]
Y_OFFSET:        991 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       908
Y_GRB_POS:       1151
BINNING_INDEX:   1
IM_URL:          sw01114034000msuni0205.fits
SUN_POSTN:       100.19d {+06h 40m 47s}  +23.10d {+23d 06' 17"}
SUN_DIST:         95.23 [deg]   Sun_angle= -9.5 [hr] (East of Sun)
MOON_POSTN:      125.69d {+08h 22m 45s}  +24.36d {+24d 21' 33"}
MOON_DIST:        83.96 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:       85.53, 44.66 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      207.06, 72.86 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 01 Jul 22 05:00:01 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1114034,   Seg_Num: 0
GRB_RA:          242.5056d {+16h 10m 01.34s} (J2000),
                 242.6328d {+16h 10m 31.88s} (current),
                 242.2236d {+16h 08m 53.65s} (1950)
GRB_DEC:         +55.4067d {+55d 24' 24.1"} (J2000),
                 +55.3490d {+55d 20' 56.4"} (current),
                 +55.5358d {+55d 32' 09.0"} (1950)
GRB_ERROR:       4.2 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  19761 TJD;   182 DOY;   22/07/01
IMG_START_TIME:  17766.00 SOD {04:56:06.00} UT,   187.9 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       100.19d {+06h 40m 47s}  +23.10d {+23d 06' 17"}
SUN_DIST:         95.26 [deg]   Sun_angle= -9.5 [hr] (East of Sun)
MOON_POSTN:      125.69d {+08h 22m 44s}  +24.36d {+24d 21' 35"}
MOON_DIST:        84.00 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:       85.49, 44.63 [deg] galactic lon,lat of the burst
ECL_COORDS:      207.18, 72.86 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 01 Jul 22 05:00:24 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1114034,   Seg_Num: 0
POINT_RA:        242.450d {+16h 09m 48s} (J2000)
POINT_DEC:       +55.425d {+55d 25' 32"} (J2000)
ROLL:            325.607d
IMG_START_DATE:  19761 TJD;   182 DOY;   22/07/01
IMG_START_TIME:  17753.15 SOD {04:55:53.15} UT,   175.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     678344182
X_OFFSET:        748 [pixels]
Y_OFFSET:        991 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       908
Y_GRB_POS:       1151
BINNING_INDEX:   1
IM_URL:          sw01114034000msuni0205.fits
SUN_POSTN:       100.19d {+06h 40m 47s}  +23.10d {+23d 06' 17"}
SUN_DIST:         95.23 [deg]   Sun_angle= -9.5 [hr] (East of Sun)
MOON_POSTN:      125.69d {+08h 22m 45s}  +24.36d {+24d 21' 32"}
MOON_DIST:        83.96 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:       85.53, 44.66 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      207.06, 72.86 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN Circular #32306
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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 01 Jul 22 05:23:16 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1114034,   Seg_Num: 0
POINT_RA:        242.448d {+16h 09m 48s} (J2000)
POINT_DEC:       +55.425d {+55d 25' 32"} (J2000)
ROLL:            325.604d
IMG_START_DATE:  19761 TJD;   182 DOY;   22/07/01
IMG_START_TIME:  18443.26 SOD {05:07:23.26} UT,   865.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     678344872
X_OFFSET:        748 [pixels]
Y_OFFSET:        991 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       908
Y_GRB_POS:       1151
BINNING_INDEX:   1
IM_URL:          sw01114034000msuni0895.fits
SUN_POSTN:       100.21d {+06h 40m 51s}  +23.10d {+23d 06' 13"}
SUN_DIST:         95.23 [deg]   Sun_angle= -9.5 [hr] (East of Sun)
MOON_POSTN:      125.89d {+08h 23m 34s}  +24.32d {+24d 19' 14"}
MOON_DIST:        83.90 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:       85.53, 44.66 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      207.06, 72.86 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 01 Jul 22 05:23:24 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1114034,   Seg_Num: 0
POINT_RA:        242.448d {+16h 09m 48s} (J2000)
POINT_DEC:       +55.425d {+55d 25' 32"} (J2000)
ROLL:            325.604d
IMG_START_DATE:  19761 TJD;   182 DOY;   22/07/01
IMG_START_TIME:  18443.26 SOD {05:07:23.26} UT,   865.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     678344872
X_OFFSET:        748 [pixels]
Y_OFFSET:        991 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       908
Y_GRB_POS:       1151
BINNING_INDEX:   1
IM_URL:          sw01114034000msuni0895.fits
SUN_POSTN:       100.21d {+06h 40m 51s}  +23.10d {+23d 06' 13"}
SUN_DIST:         95.23 [deg]   Sun_angle= -9.5 [hr] (East of Sun)
MOON_POSTN:      125.89d {+08h 23m 34s}  +24.32d {+24d 19' 13"}
MOON_DIST:        83.90 [deg]
MOON_ILLUM:      4 [%]
GAL_COORDS:       85.53, 44.66 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      207.06, 72.86 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN Circular #32307
WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to Swift GRB 200701A (Evans al., GCN 32306) starting at 04:57:09 UT, 251 s after the burst. Observations were performed with an automatic sequence in the clear (roughly R), V, and I filters, and the exposure time was 20 s per image. Our first few images were out-focused, and the first useful focused image started at 05:07:57 UT. In the aftward focused images, we do not detect any optical afterglow candidate within the reported XRT position error circle (Evans et al., GCN 32306), neither in single image, nor in the co-add images. The typical limiting magnitude of our single clear image is about 18.5 mag calibrated to the Pan-STARRS1 catalog.
GCN Circular #32308
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
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
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
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
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
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
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
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
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
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
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
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/

Back to JG's homepage

Jochen Greiner, last update: 06-Jul-2022 [Disclaimer]