Gamma-ray Burst 221121A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Mon 21 Nov 22 06:35:28 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      61
TRIGGER_NUM:     690705294
GRB_RA:          110.733d {+07h 22m 56s} (J2000),
                 111.370d {+07h 25m 29s} (current),
                 109.334d {+07h 17m 20s} (1950)
GRB_DEC:         +70.933d {+70d 55' 60"} (J2000),
                 +70.888d {+70d 53' 15"} (current),
                 +71.029d {+71d 01' 43"} (1950)
GRB_ERROR:       8.95 [deg radius, statistical plus systematic]
GRB_INTEN:       308 [cnts/sec]
DATA_SIGNIF:     27.50 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        19904 TJD;   325 DOY;   22/11/21
GRB_TIME:        23689.74 SOD {06:34:49.74} UT
GRB_PHI:         167.00 [deg]
GRB_THETA:        35.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.29
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      97%  GRB
2nd_MOST_LIKELY:   1%  Generic Transient
DETECTORS:       0,0,0, 0,0,0, 1,1,0, 0,0,0, 0,0,
SUN_POSTN:       236.70d {+15h 46m 48s}  -19.92d {-19d 54' 55"}
SUN_DIST:        119.99 [deg]   Sun_angle= 8.4 [hr] (West of Sun)
MOON_POSTN:      202.73d {+13h 30m 55s}   -7.61d {-07d 36' 47"}
MOON_DIST:        97.64 [deg]
MOON_ILLUM:      9 [%]
GAL_COORDS:      144.45, 28.09 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       99.99, 48.21 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221121274/quicklook/glg_lc_medres34_bn221121274.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 52.13,15.05 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(2.0<100sec) coincident with the CALET_GBM event (trignum=1353047657).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Mon 21 Nov 22 06:35:19 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      49
TRIGGER_NUM:     690705294
GRB_RA:          163.650d {+10h 54m 36s} (J2000),
                 164.113d {+10h 56m 27s} (current),
                 162.616d {+10h 50m 28s} (1950)
GRB_DEC:         +78.267d {+78d 16' 00"} (J2000),
                 +78.144d {+78d 08' 39"} (current),
                 +78.533d {+78d 31' 59"} (1950)
GRB_ERROR:       7.32 [deg radius, statistical plus systematic]
GRB_INTEN:       660 [cnts/sec]
DATA_SIGNIF:     18.20 [sigma]
INTEG_TIME:      0.512 [sec]
GRB_DATE:        19904 TJD;   325 DOY;   22/11/21
GRB_TIME:        23689.74 SOD {06:34:49.74} UT
GRB_PHI:         144.00 [deg]
GRB_THETA:        25.00 [deg]
DATA_TIME_SCALE: 0.5120 [sec]
HARD_RATIO:      0.37
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      96%  GRB
2nd_MOST_LIKELY:   3%  Generic Transient
DETECTORS:       0,0,0, 0,0,0, 1,1,0, 0,0,0, 0,0,
SUN_POSTN:       236.70d {+15h 46m 48s}  -19.92d {-19d 54' 55"}
SUN_DIST:        106.00 [deg]   Sun_angle= 4.8 [hr] (West of Sun)
MOON_POSTN:      202.73d {+13h 30m 55s}   -7.61d {-07d 36' 45"}
MOON_DIST:        88.31 [deg]
MOON_ILLUM:      9 [%]
GAL_COORDS:      130.09, 37.19 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      113.82, 61.11 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221121274/quicklook/glg_lc_medres34_bn221121274.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 52.13,15.05 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(2.0<100sec) coincident with the CALET_GBM event (trignum=1353047657).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Mon 21 Nov 22 06:35:37 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      60
TRIGGER_NUM:     690705294
GRB_RA:          165.370d {+11h 01m 29s} (J2000),
                 165.757d {+11h 03m 02s} (current),
                 164.514d {+10h 58m 03s} (1950)
GRB_DEC:         +71.290d {+71d 17' 24"} (J2000),
                 +71.167d {+71d 09' 60"} (current),
                 +71.559d {+71d 33' 32"} (1950)
GRB_ERROR:       2.91 [deg radius, statistical only]
DATA_SIGNIF:     24.30 [sigma]
DATA_INTERVAL:   2.048 [sec]
GRB_DATE:        19904 TJD;   325 DOY;   22/11/21
GRB_TIME:        23689.74 SOD {06:34:49.74} UT
GRB_PHI:         154.00 [deg]
GRB_THETA:        19.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4173 (Gnd S/W Version number)
SUN_POSTN:       236.70d {+15h 46m 48s}  -19.92d {-19d 54' 55"}
SUN_DIST:        102.90 [deg]   Sun_angle= 4.7 [hr] (West of Sun)
MOON_POSTN:      202.73d {+13h 30m 56s}   -7.61d {-07d 36' 49"}
MOON_DIST:        82.52 [deg]
MOON_ILLUM:      9 [%]
GAL_COORDS:      134.66, 43.25 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      124.53, 56.80 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221121274/quicklook/glg_lc_medres34_bn221121274.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_690705294.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        Bright hard burst in the GBM.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(2.0<100sec) coincident with the CALET_GBM event (trignum=1353047657).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Mon 21 Nov 22 06:43:58 UT
NOTICE_TYPE:     Fermi-GBM Final Position
RECORD_NUM:      0
TRIGGER_NUM:     690705294
GRB_RA:          168.830d {+11h 15m 19s} (J2000),
                 169.194d {+11h 16m 47s} (current),
                 168.025d {+11h 12m 06s} (1950)
GRB_DEC:         +71.090d {+71d 05' 24"} (J2000),
                 +70.965d {+70d 57' 54"} (current),
                 +71.363d {+71d 21' 46"} (1950)
GRB_ERROR:       1.11 [deg radius, statistical only]
GRB_DATE:        19904 TJD;   325 DOY;   22/11/21
GRB_TIME:        23689.74 SOD {06:34:49.74} UT
GRB_PHI:         152.00 [deg]
GRB_THETA:        18.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       236.71d {+15h 46m 49s}  -19.92d {-19d 55' 00"}
SUN_DIST:        101.81 [deg]   Sun_angle= 4.5 [hr] (West of Sun)
MOON_POSTN:      202.80d {+13h 31m 13s}   -7.65d {-07d 38' 55"}
MOON_DIST:        81.76 [deg]
MOON_ILLUM:      9 [%]
GAL_COORDS:      133.51, 44.01 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      126.23, 57.46 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221121274/quicklook/glg_lc_medres34_bn221121274.gif
LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221121274/quicklook/glg_locplot_all_bn221121274.png
COMMENTS:        Fermi-GBM Final Position.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file should be available by the time this FINAL notice is produced.  
COMMENTS:        This notice was generated completely by automated pipeline processing.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        Bright hard burst in the GBM.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(2.0<100sec) coincident with the CALET_GBM event (trignum=1353047657).

GCN Circular #32960
The Fermi GBM team reports the detection of a likely LONG GRB
At 06:34:49 UT on 21 Nov 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 221121A (trigger 690705294.743784 / 221121274).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 168.8, Dec = 71.1 (J2000 degrees, equivalent to J2000 11h 15m, 71d 05'), with a statistical uncertainty of 1.1 degrees.
The angle from the Fermi LAT boresight is 18.0 degrees.
The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221121274/quicklook/glg_skymap_all_bn221121274.png
The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221121274/quicklook/glg_healpix_all_bn221121274.fit
The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221121274/quicklook/glg_lc_medres34_bn221121274.gif
GCN Circular #32969
R. Gopalakrishnan (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long GRB221121A which was also detected by Fermi GBM (GCN Circ. 32960).
The source was clearly detected in the 20-200 keV energy range. The light curve peaks at 2022-11-21 06:34:50.5 UTC. The measured peak count rate associated with the burst is 173 (+42, -40) counts/s above the background in the combined data of all quadrants, with a total of 1531 (+490, -529) counts. The local mean background count rate was 532 (+3, -4) counts/s. Using cumulative rates, we measure a T90 of 22 (+15, -9) s.
It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2022-11-21 06:34:53.9 UTC. The measured peak count rate is 283 (+79, -30) counts/s above the background in the combined Veto data of all quadrants, with a total of 3488 (+696, -662) counts. The local mean background count rate was 1746 (+6, -6) counts/s. We measure a T90 of 22 (+10, -4) s from the cumulative Veto light curve.
CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.
GCN Circular #32971
A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the MGNS/BepiColombo team,
J. Benkhoff on behalf of the BepiColombo team,
A. Ridnaia, D. Frederiks, D. Svinkin, A. Lysenko, and T. Cline on behalf of the Konus-Wind team,
A. Goldstein, M. S. Briggs, and C. Wilson-Hodge on behalf of the Fermi GBM team,
E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
and
S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu on behalf of the Swift-BAT team, report:
The long-duration GRB 221121A (Fermi-GBM detection: Fermi GBM Team, GCN Circ. 32960; AstroSat-CZTI detection: Gopalakrishnan et al., GCN Circ. 32969) has been detected by Fermi (GBM trigger 690705294), Konus-Wind, INTEGRAL (SPI-ACS), AstroSat (CZTI), CALET (CGBM), GECAM-B (trigger tn221121_063449_fb), Swift (BAT), and BepiColombo (MGNS), so far, at about 23690 s UT (06:34:50). The burst was outside the coded field of view of the BAT.
We have triangulated it to a preliminary, 3 sigma error box whose coordinates are:
```
 ---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
  163.104 (10h 52m 25s) +69.356 (+69d 21' 22")
 Corners:
  164.660 (10h 58m 38s) +69.887 (+69d 53' 12")
  164.681 (10h 58m 43s) +70.133 (+70d 08' 00")
  161.617 (10h 46m 28s) +68.809 (+68d 48' 31")
  161.623 (10h 46m 30s) +68.558 (+68d 33' 29")
 ---------------------------------------------
```
The error box area is 952 sq. arcmin, and its maximum dimension is 1.9 deg (the minimum one is 9 arcmin). The Sun distance was about 103 deg.
This localization may be improved.
The IPN localization is consistent with, but reduces the area of, the Fermi-GBM final localization (GCN Circ. 32960).
A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB221121_T23691/IPN
The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular.
GCN Circular #32974
T. Sakamoto, A. Yoshida, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration:
The long GRB 221121A (Fermi GBM Final Real-time Localization: Fermi GBM team, GCN Circ. 32960; AstroSat CZTI detection: Gopalakrishnan et al., GCN Circ 32969; IPN triangulation: Kozyrev etc al., GCN Circ. 32971) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 06:34:47.10 UTC on 21 November 2022 (http://cgbm.calet.jp/cgbm_trigger/flight/1353047657/index.html). The burst signal was seen by only SGM detector.
The burst light curve shows a single pulse which starts at T+2.6 sec, peaks at T+3.1 sec, and ends at T+30.2 sec. The T90 and T50 durations measured by the SGM data are 24.1 +/- 0.8 sec and 10.1 +/- 1.7 sec (40-1000 keV), respectively.
The ground processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1353047657/
The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.

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Jochen Greiner, last update: 23-Nov-2022 [Disclaimer]