Gamma-ray Burst 220325A

(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 25 Mar 22 17:16:36 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1099310,   Seg_Num: 0
GRB_RA:          269.485d {+17h 57m 56s} (J2000),
                 269.785d {+17h 59m 08s} (current),
                 268.810d {+17h 55m 15s} (1950)
GRB_DEC:          -7.031d {-07d 01' 50"} (J2000),
                  -7.031d {-07d 01' 52"} (current),
                  -7.027d {-07d 01' 35"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       4056 [cnts]    Image_Peak=234 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   137     E_range: 15-50 keV
BKG_INTEN:       24316 [cnts]
BKG_TIME:        62171.15 SOD {17:16:11.15} UT
BKG_DUR:         8 [sec]
GRB_DATE:        19663 TJD;    84 DOY;   22/03/25
GRB_TIME:        62183.05 SOD {17:16:23.05} UT
GRB_PHI:         -25.47 [deg]
GRB_THETA:        38.41 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     15.84 [sigma]
IMAGE_SIGNIF:    10.22 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +1  +0  +0  +1  +9  +0 
SUN_POSTN:         4.63d {+00h 18m 30s}   +2.00d {+02d 00' 08"}
SUN_DIST:         95.05 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      282.67d {+18h 50m 41s}  -26.76d {-26d 45' 48"}
MOON_DIST:        23.22 [deg]
MOON_ILLUM:      45 [%]
GAL_COORDS:       20.46,  8.54 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      269.47, 16.41 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
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 = 189.97,20.46 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Mar 22 17:18:19 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     1099310,   Seg_Num: 0
POINT_RA:        269.483d {+17h 57m 56s} (J2000)
POINT_DEC:        -7.018d {-07d 01' 03"} (J2000)
IMG_START_DATE:  19663 TJD;    84 DOY;   22/03/25
IMG_START_TIME:  62293.26 SOD {17:18:13.26} UT,   110.2 [sec] since BAT Trigger Time
COUNTS:          2    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        1    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Mar 22 17:20:14 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1099310,   Seg_Num: 0
GRB_RA:          269.485d {+17h 57m 56s} (J2000),
                 269.785d {+17h 59m 08s} (current),
                 268.810d {+17h 55m 15s} (1950)
GRB_DEC:          -7.031d {-07d 01' 50"} (J2000),
                  -7.031d {-07d 01' 52"} (current),
                  -7.027d {-07d 01' 35"} (1950)
GRB_DATE:        19663 TJD;    84 DOY;   22/03/25
GRB_TIME:        62183.05 SOD {17:16:23.05} UT
TRIGGER_INDEX:   137
GRB_PHI:         -25.47 [deg]
GRB_THETA:        38.41 [deg]
DELTA_TIME:      -69.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     15.84 [sigma]
IMAGE_SIGNIF:    10.22 [sigma]
LC_URL:          sw01099310000msb.lc
SUN_POSTN:         4.63d {+00h 18m 31s}   +2.00d {+02d 00' 12"}
SUN_DIST:         95.05 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      282.71d {+18h 50m 50s}  -26.76d {-26d 45' 45"}
MOON_DIST:        23.24 [deg]
MOON_ILLUM:      44 [%]
GAL_COORDS:       20.46,  8.54 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      269.47, 16.41 [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 = 189.97,20.46 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Mar 22 17:21:07 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1099310,   Seg_Num: 0
POINT_RA:        269.483d {+17h 57m 56s} (J2000)
POINT_DEC:        -7.017d {-07d 01' 02"} (J2000)
POINT_ROLL:      88.621d
IMG_START_DATE:  19663 TJD;    84 DOY;   22/03/25
IMG_START_TIME:  62297.39 SOD {17:18:17.39} UT,   114.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.707
N_STARS:         110
X_OFFSET:        546 [pixels]
Y_OFFSET:        632 [pixels]
X_MAX:           1505 [pixels]
Y_MAX:           1591 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw01099310000msufc0114.fits
SUN_POSTN:         4.63d {+00h 18m 31s}   +2.00d {+02d 00' 13"}
SUN_DIST:         95.05 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      282.72d {+18h 50m 53s}  -26.76d {-26d 45' 44"}
MOON_DIST:        23.26 [deg]
MOON_ILLUM:      44 [%]
GAL_COORDS:       20.47,  8.55 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      269.46, 16.42 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Mar 22 17:21:26 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1099310,   Seg_Num: 0
POINT_RA:        269.483d {+17h 57m 56s} (J2000)
POINT_DEC:        -7.017d {-07d 01' 02"} (J2000)
POINT_ROLL:      88.621d
IMG_START_DATE:  19663 TJD;    84 DOY;   22/03/25
IMG_START_TIME:  62297.39 SOD {17:18:17.39} UT,   114.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.707
N_STARS:         110
X_OFFSET:        546 [pixels]
Y_OFFSET:        632 [pixels]
X_MAX:           1505 [pixels]
Y_MAX:           1591 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw01099310000msufc0114.fits
SUN_POSTN:         4.63d {+00h 18m 31s}   +2.00d {+02d 00' 13"}
SUN_DIST:         95.05 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      282.72d {+18h 50m 53s}  -26.76d {-26d 45' 44"}
MOON_DIST:        23.26 [deg]
MOON_ILLUM:      44 [%]
GAL_COORDS:       20.47,  8.55 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      269.46, 16.42 [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 25 Mar 22 17:22:52 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1099310,   Seg_Num: 0
POINT_RA:        269.483d {+17h 57m 56s} (J2000)
POINT_DEC:        -7.017d {-07d 01' 02"} (J2000)
ROLL:            88.621d
IMG_START_DATE:  19663 TJD;    84 DOY;   22/03/25
IMG_START_TIME:  62297.39 SOD {17:18:17.39} UT,   114.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     669921526
X_OFFSET:        865 [pixels]
Y_OFFSET:        951 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1025
Y_GRB_POS:       1111
BINNING_INDEX:   1
IM_URL:          sw01099310000msuni0143.fits
SUN_POSTN:         4.63d {+00h 18m 31s}   +2.00d {+02d 00' 14"}
SUN_DIST:         95.05 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      282.74d {+18h 50m 57s}  -26.76d {-26d 45' 42"}
MOON_DIST:        23.27 [deg]
MOON_ILLUM:      44 [%]
GAL_COORDS:       20.47,  8.55 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      269.46, 16.42 [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 25 Mar 22 17:21:57 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1099310,   Seg_Num: 0
GRB_RA:          269.4875d {+17h 57m 57.00s} (J2000),
                 269.7876d {+17h 59m 09.02s} (current),
                 268.8126d {+17h 55m 15.02s} (1950)
GRB_DEC:          -7.0377d {-07d 02' 15.7"} (J2000),
                  -7.0385d {-07d 02' 18.5"} (current),
                  -7.0336d {-07d 02' 00.8"} (1950)
GRB_ERROR:       3.9 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  19663 TJD;    84 DOY;   22/03/25
IMG_START_TIME:  62307.00 SOD {17:18:27.00} UT,   123.9 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:         4.63d {+00h 18m 31s}   +2.00d {+02d 00' 13"}
SUN_DIST:         95.05 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      282.73d {+18h 50m 55s}  -26.76d {-26d 45' 43"}
MOON_DIST:        23.25 [deg]
MOON_ILLUM:      44 [%]
GAL_COORDS:       20.45,  8.53 [deg] galactic lon,lat of the burst
ECL_COORDS:      269.47, 16.40 [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 25 Mar 22 17:23:05 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1099310,   Seg_Num: 0
POINT_RA:        269.483d {+17h 57m 56s} (J2000)
POINT_DEC:        -7.017d {-07d 01' 02"} (J2000)
ROLL:            88.621d
IMG_START_DATE:  19663 TJD;    84 DOY;   22/03/25
IMG_START_TIME:  62297.39 SOD {17:18:17.39} UT,   114.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     669921526
X_OFFSET:        865 [pixels]
Y_OFFSET:        951 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1025
Y_GRB_POS:       1111
BINNING_INDEX:   1
IM_URL:          sw01099310000msuni0143.fits
SUN_POSTN:         4.63d {+00h 18m 31s}   +2.00d {+02d 00' 15"}
SUN_DIST:         95.05 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      282.74d {+18h 50m 58s}  -26.76d {-26d 45' 42"}
MOON_DIST:        23.27 [deg]
MOON_ILLUM:      44 [%]
GAL_COORDS:       20.47,  8.55 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      269.46, 16.42 [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 #31787
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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Mar 22 17:28:44 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1099310,   Seg_Num: 0
POINT_RA:        269.482d {+17h 57m 56s} (J2000)
POINT_DEC:        -7.017d {-07d 01' 00"} (J2000)
POINT_ROLL:      88.620d
IMG_START_DATE:  19663 TJD;    84 DOY;   22/03/25
IMG_START_TIME:  62509.56 SOD {17:21:49.56} UT,   326.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.197
N_STARS:         43
X_OFFSET:        306 [pixels]
Y_OFFSET:        392 [pixels]
X_MAX:           1745 [pixels]
Y_MAX:           1831 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw01099310000msufc0326.fits
SUN_POSTN:         4.63d {+00h 18m 32s}   +2.01d {+02d 00' 20"}
SUN_DIST:         95.06 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      282.80d {+18h 51m 13s}  -26.76d {-26d 45' 37"}
MOON_DIST:        23.30 [deg]
MOON_ILLUM:      44 [%]
GAL_COORDS:       20.47,  8.55 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      269.46, 16.42 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Mar 22 17:30:09 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1099310,   Seg_Num: 0
POINT_RA:        269.482d {+17h 57m 56s} (J2000)
POINT_DEC:        -7.017d {-07d 01' 00"} (J2000)
ROLL:            88.620d
IMG_START_DATE:  19663 TJD;    84 DOY;   22/03/25
IMG_START_TIME:  62509.56 SOD {17:21:49.56} UT,   326.5 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     669921738
X_OFFSET:        865 [pixels]
Y_OFFSET:        951 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1025
Y_GRB_POS:       1111
BINNING_INDEX:   1
IM_URL:          sw01099310000msuni0355.fits
SUN_POSTN:         4.64d {+00h 18m 32s}   +2.01d {+02d 00' 22"}
SUN_DIST:         95.06 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      282.82d {+18h 51m 16s}  -26.76d {-26d 45' 35"}
MOON_DIST:        23.31 [deg]
MOON_ILLUM:      44 [%]
GAL_COORDS:       20.47,  8.55 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      269.46, 16.42 [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 25 Mar 22 17:29:00 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1099310,   Seg_Num: 0
POINT_RA:        269.482d {+17h 57m 56s} (J2000)
POINT_DEC:        -7.017d {-07d 01' 00"} (J2000)
POINT_ROLL:      88.620d
IMG_START_DATE:  19663 TJD;    84 DOY;   22/03/25
IMG_START_TIME:  62509.56 SOD {17:21:49.56} UT,   326.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.197
N_STARS:         43
X_OFFSET:        306 [pixels]
Y_OFFSET:        392 [pixels]
X_MAX:           1745 [pixels]
Y_MAX:           1831 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw01099310000msufc0326.fits
SUN_POSTN:         4.63d {+00h 18m 32s}   +2.01d {+02d 00' 20"}
SUN_DIST:         95.06 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      282.81d {+18h 51m 13s}  -26.76d {-26d 45' 37"}
MOON_DIST:        23.30 [deg]
MOON_ILLUM:      44 [%]
GAL_COORDS:       20.47,  8.55 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      269.46, 16.42 [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 25 Mar 22 17:30:16 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1099310,   Seg_Num: 0
POINT_RA:        269.482d {+17h 57m 56s} (J2000)
POINT_DEC:        -7.017d {-07d 01' 00"} (J2000)
ROLL:            88.620d
IMG_START_DATE:  19663 TJD;    84 DOY;   22/03/25
IMG_START_TIME:  62509.56 SOD {17:21:49.56} UT,   326.5 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     669921738
X_OFFSET:        865 [pixels]
Y_OFFSET:        951 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1025
Y_GRB_POS:       1111
BINNING_INDEX:   1
IM_URL:          sw01099310000msuni0355.fits
SUN_POSTN:         4.64d {+00h 18m 32s}   +2.01d {+02d 00' 22"}
SUN_DIST:         95.06 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      282.82d {+18h 51m 17s}  -26.76d {-26d 45' 35"}
MOON_DIST:        23.31 [deg]
MOON_ILLUM:      44 [%]
GAL_COORDS:       20.47,  8.55 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      269.46, 16.42 [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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Mar 22 17:34:51 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1099310,   Seg_Num: 0
POINT_RA:        269.481d {+17h 57m 56s} (J2000)
POINT_DEC:        -7.017d {-07d 01' 00"} (J2000)
POINT_ROLL:      88.621d
IMG_START_DATE:  19663 TJD;    84 DOY;   22/03/25
IMG_START_TIME:  63040.68 SOD {17:30:40.68} UT,   857.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        6.614
N_STARS:         190
X_OFFSET:        306 [pixels]
Y_OFFSET:        392 [pixels]
X_MAX:           1745 [pixels]
Y_MAX:           1831 [pixels]
DET_THRESH:      22
PHOTO_THRESH:    13
SL_URL:          sw01099310000msufc0857.fits
SUN_POSTN:         4.64d {+00h 18m 33s}   +2.01d {+02d 00' 26"}
SUN_DIST:         95.06 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      282.87d {+18h 51m 29s}  -26.76d {-26d 45' 31"}
MOON_DIST:        23.33 [deg]
MOON_ILLUM:      44 [%]
GAL_COORDS:       20.47,  8.55 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      269.46, 16.42 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Mar 22 17:35:04 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1099310,   Seg_Num: 0
POINT_RA:        269.481d {+17h 57m 56s} (J2000)
POINT_DEC:        -7.017d {-07d 01' 00"} (J2000)
POINT_ROLL:      88.621d
IMG_START_DATE:  19663 TJD;    84 DOY;   22/03/25
IMG_START_TIME:  63040.68 SOD {17:30:40.68} UT,   857.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        6.614
N_STARS:         190
X_OFFSET:        306 [pixels]
Y_OFFSET:        392 [pixels]
X_MAX:           1745 [pixels]
Y_MAX:           1831 [pixels]
DET_THRESH:      22
PHOTO_THRESH:    13
SL_URL:          sw01099310000msufc0857.fits
SUN_POSTN:         4.64d {+00h 18m 33s}   +2.01d {+02d 00' 26"}
SUN_DIST:         95.06 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      282.87d {+18h 51m 29s}  -26.76d {-26d 45' 31"}
MOON_DIST:        23.34 [deg]
MOON_ILLUM:      44 [%]
GAL_COORDS:       20.47,  8.55 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      269.46, 16.42 [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 25 Mar 22 17:37:10 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1099310,   Seg_Num: 0
POINT_RA:        269.481d {+17h 57m 56s} (J2000)
POINT_DEC:        -7.017d {-07d 01' 00"} (J2000)
ROLL:            88.621d
IMG_START_DATE:  19663 TJD;    84 DOY;   22/03/25
IMG_START_TIME:  63040.68 SOD {17:30:40.68} UT,   857.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     669922269
X_OFFSET:        865 [pixels]
Y_OFFSET:        951 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1025
Y_GRB_POS:       1111
BINNING_INDEX:   1
IM_URL:          sw01099310000msuni0886.fits
SUN_POSTN:         4.64d {+00h 18m 34s}   +2.01d {+02d 00' 28"}
SUN_DIST:         95.07 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      282.90d {+18h 51m 35s}  -26.76d {-26d 45' 29"}
MOON_DIST:        23.35 [deg]
MOON_ILLUM:      44 [%]
GAL_COORDS:       20.47,  8.55 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      269.46, 16.42 [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 25 Mar 22 17:37:17 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1099310,   Seg_Num: 0
POINT_RA:        269.481d {+17h 57m 56s} (J2000)
POINT_DEC:        -7.017d {-07d 01' 00"} (J2000)
ROLL:            88.621d
IMG_START_DATE:  19663 TJD;    84 DOY;   22/03/25
IMG_START_TIME:  63040.68 SOD {17:30:40.68} UT,   857.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     669922269
X_OFFSET:        865 [pixels]
Y_OFFSET:        951 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1025
Y_GRB_POS:       1111
BINNING_INDEX:   1
IM_URL:          sw01099310000msuni0886.fits
SUN_POSTN:         4.64d {+00h 18m 34s}   +2.01d {+02d 00' 29"}
SUN_DIST:         95.07 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      282.90d {+18h 51m 35s}  -26.76d {-26d 45' 29"}
MOON_DIST:        23.35 [deg]
MOON_ILLUM:      44 [%]
GAL_COORDS:       20.47,  8.55 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      269.46, 16.42 [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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Mar 22 17:50:04 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     1099310,   Seg_Num: 0
GRB_RA:          269.4874d {+17h 57m 56.97s} (J2000),
                 269.7875d {+17h 59m 09.00s} (current),
                 268.8125d {+17h 55m 15.00s} (1950)
GRB_DEC:          -7.0369d {-07d 02' 12.8"} (J2000),
                  -7.0377d {-07d 02' 15.6"} (current),
                  -7.0328d {-07d 01' 57.9"} (1950)
GRB_ERROR:       3.7 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  19663 TJD;    84 DOY;   22/03/25
IMG_START_TIME:  62307.00 SOD {17:18:27.00} UT,   123.9 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:         4.65d {+00h 18m 35s}   +2.01d {+02d 00' 41"}
SUN_DIST:         95.07 [deg]   Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN:      283.04d {+18h 52m 09s}  -26.75d {-26d 45' 16"}
MOON_DIST:        23.40 [deg]
MOON_ILLUM:      44 [%]
GAL_COORDS:       20.45,  8.54 [deg] galactic lon,lat of the burst
ECL_COORDS:      269.47, 16.40 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
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 Circular #31789
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
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
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
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
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
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
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
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
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
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/).

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Jochen Greiner, last update: 29-Mar-2022 [Disclaimer]