Gamma-ray Burst 221022A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 22 Oct 22 19:34:03 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      44
TRIGGER_NUM:     688160018
GRB_RA:          129.067d {+08h 36m 16s} (J2000),
                 129.324d {+08h 37m 18s} (current),
                 128.502d {+08h 34m 00s} (1950)
GRB_DEC:         -19.283d {-19d 16' 59"} (J2000),
                 -19.364d {-19d 21' 48"} (current),
                 -19.109d {-19d 06' 31"} (1950)
GRB_ERROR:       31.08 [deg radius, statistical plus systematic]
GRB_INTEN:       72 [cnts/sec]
DATA_SIGNIF:     4.50 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        19874 TJD;   295 DOY;   22/10/22
GRB_TIME:        70413.55 SOD {19:33:33.55} UT
GRB_PHI:         310.00 [deg]
GRB_THETA:       115.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.58
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      95%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       0,0,0, 0,1,1, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       207.32d {+13h 49m 17s}  -11.25d {-11d 15' 05"}
SUN_DIST:         75.10 [deg]   Sun_angle= 5.2 [hr] (West of Sun)
MOON_POSTN:      178.59d {+11h 54m 20s}   +4.84d {+04d 50' 17"}
MOON_DIST:        54.16 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:      242.68, 12.73 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      137.71,-36.48 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221022815/quicklook/glg_lc_medres34_bn221022815.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 246.97,-6.20 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 22 Oct 22 19:34:21 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      57
TRIGGER_NUM:     688160018
GRB_RA:          130.820d {+08h 43m 17s} (J2000),
                 131.081d {+08h 44m 19s} (current),
                 130.249d {+08h 41m 00s} (1950)
GRB_DEC:         -18.160d {-18d 09' 35"} (J2000),
                 -18.243d {-18d 14' 35"} (current),
                 -17.979d {-17d 58' 44"} (1950)
GRB_ERROR:       12.44 [deg radius, statistical only]
DATA_SIGNIF:     6.70 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        19874 TJD;   295 DOY;   22/10/22
GRB_TIME:        70413.55 SOD {19:33:33.55} UT
GRB_PHI:         310.00 [deg]
GRB_THETA:       113.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4173 (Gnd S/W Version number)
SUN_POSTN:       207.32d {+13h 49m 17s}  -11.25d {-11d 15' 05"}
SUN_DIST:         73.58 [deg]   Sun_angle= 5.1 [hr] (West of Sun)
MOON_POSTN:      178.59d {+11h 54m 21s}   +4.84d {+04d 50' 13"}
MOON_DIST:        52.20 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:      242.73, 14.74 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      139.22,-34.89 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221022815/quicklook/glg_lc_medres34_bn221022815.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_688160018.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
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.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 22 Oct 22 19:40:47 UT
NOTICE_TYPE:     Fermi-GBM Final Position
RECORD_NUM:      0
TRIGGER_NUM:     688160018
GRB_RA:          126.580d {+08h 26m 19s} (J2000),
                 126.840d {+08h 27m 22s} (current),
                 126.011d {+08h 24m 03s} (1950)
GRB_DEC:         -17.710d {-17d 42' 35"} (J2000),
                 -17.786d {-17d 47' 08"} (current),
                 -17.545d {-17d 32' 42"} (1950)
GRB_ERROR:       11.42 [deg radius, statistical only]
GRB_DATE:        19874 TJD;   295 DOY;   22/10/22
GRB_TIME:        70413.55 SOD {19:33:33.55} UT
GRB_PHI:         307.00 [deg]
GRB_THETA:       116.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       207.32d {+13h 49m 18s}  -11.25d {-11d 15' 11"}
SUN_DIST:         77.64 [deg]   Sun_angle= 5.4 [hr] (West of Sun)
MOON_POSTN:      178.64d {+11h 54m 33s}   +4.81d {+04d 48' 38"}
MOON_DIST:        55.86 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:      239.99, 11.67 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      134.34,-35.69 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221022815/quicklook/glg_lc_medres34_bn221022815.gif
LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221022815/quicklook/glg_locplot_all_bn221022815.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:        This is likely a Long GRB.

GCN Circular #32816
The Fermi GBM team reports the detection of a likely LONG GRB
At 19:33:33 UT on 22 Oct 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 221022A (trigger 688160018.552146 / 221022815).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 126.6, Dec = -17.7 (J2000 degrees, equivalent to J2000 08h 26m, -17d 41'), with a statistical uncertainty of 11.4 degrees.
The angle from the Fermi LAT boresight is 116.0 degrees.
The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221022815/quicklook/glg_skymap_all_bn221022815.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/bn221022815/quicklook/glg_healpix_all_bn221022815.fit
The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221022815/quicklook/glg_lc_medres34_bn221022815.gif
GCN Circular #32824
Aaron Tohuvavohu (U Toronto), Gayathri Raman (PSU), James DeLaunay (UAlabama), Jamie A. Kennea (PSU), Tyler Parsotan (GSFC/UMBC) report:
Swift/BAT did not localize GRB 221022A onboard (T0: 2022-10-22T19:33:33 UTC, Fermi/GBM GCN 32816).
The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).
Upon trigger, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground.
The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu, arXiv:2111.01769), detects the burst with a sqrt(TS) of 8.7 in a 4.096 s analysis time bin.
NITRATES results, independently, are ambiguous with respect to whether this burst originates from in or outside the BAT FOV, with a borderline DeltaLLHOut of 9.5.
The best fit In FOV position is very weakly preferred over other positions, with DeltaLLHPeak of 2.1. This position is consistent with the Fermi/GBM localization (GCN 32816).
The candidate position is RA, Dec = 118.342, -5.117 which is
```
   RA(J2000)  = 07h 53m 22.03s
   Dec(J2000) = -5d 07′ 00.9″
```
with an estimated uncertainty of 5 arcmin.
See Section 9.1 and Figure 20 in the NITRATES paper for brief descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut.
GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches.
A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/
GCN Circular #32833
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the Swift/BAT-GUANO GRB 221022A. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021530
Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the Swift/BAT-GUANO event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration.
Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).
This circular is an official product of the Swift-XRT team.
GCN Circular #32834
S. Poolakkil (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:
"At 19:33:33.55 UT on 22 October 2022, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 221022A (trigger 688160018 / 221022815, GCN 32816) which was also detected by the Swift/BAT- GUANO (Tohuvavohu et al. 2022, GCN 32824). The Fermi GBM Final Real-time Localization is consistent with the Swift-BAT GUANO position.
The angle from the Fermi LAT boresight at the GBM trigger time is 115 degrees.
The GBM light curve consists of a single peak followed by some extended emission with a duration (T90) of about 7 s (50-300 keV). The time-averaged spectrum from T0-3.07 s to T0 s is best fit by a simple power law function with index -1.39 +/- 0.15.
The event fluence (10-1000 keV) in this time interval is (3.64 +/- 0.98)E-07 erg/cm^2. The 1-sec peak photon flux measured starting from T0-1.6 s in the 10-1000 keV band is 3.3 +/- 0.4 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"

GCN Circular #32847
J.P. Osborne (U. Leicester), E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR), S. Dichiara (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the Swift/BAT-GUANO-detected burst GRB 221022A (Aaron Tohuvavohu et al. GCN Circ. 32824), collecting 3.8 ks of Photon Counting (PC) mode data between T0+170.9 ks and T0+184.2 ks.
Six uncatalogued X-ray sources have been detected, however none of them is above the RASS limit or shows definitive signs of fading. None of the six is inside the GUANO error region. Therefore, at the present time we cannot identify which, if any, is the afterglow. Details of these sources are given below:
Source 1:

  RA (J2000.0):  118.4349  =  07:53:44.38
  Dec (J2000.0): -5.2165  =  -05:12:59.3
  Error: 7.7 arcsec (radius, 90% conf.)
  Count-rate: (3.1 [+1.5, -1.2])e-3 ct s^-1   
  Distance: 489 arcsec from Swift/BAT-GUANO position.

Source 2:

  RA (J2000.0):  118.3560  =  07:53:25.45
  Dec (J2000.0): -5.2797  =  -05:16:47.0
  Error: 5.3 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: (4.3 [+1.7, -1.4])e-3 ct s^-1   
  Distance: 588 arcsec from Swift/BAT-GUANO position.
  Flux: (1.12 [+0.45, -0.36])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 3:

  RA (J2000.0):  118.2368  =  07:52:56.83
  Dec (J2000.0): -5.2703  =  -05:16:13.1
  Error: 6.1 arcsec (radius, 90% conf.)
  Count-rate: (4.2 [+1.8, -1.4])e-3 ct s^-1   
  Distance: 668 arcsec from Swift/BAT-GUANO position.
  Flux: (2.14 [+0.91, -0.72])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 4:

  RA (J2000.0):  118.4804  =  07:53:55.29
  Dec (J2000.0): -5.1253  =  -05:07:31.0
  Error: 6.9 arcsec (radius, 90% conf.)
  Count-rate: (1.65 [+1.13, -0.80])e-3 ct s^-1	 
  Distance: 497 arcsec from Swift/BAT-GUANO position.

Source 5:

  RA (J2000.0):  118.1854  =  07:52:44.49
  Dec (J2000.0): -5.2601  =  -05:15:36.4
  Error: 4.1 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: (5.9 [+2.1, -1.7])e-3 ct s^-1   
  Distance: 761 arcsec from Swift/BAT-GUANO position.
  Flux: (2.22 [+0.79, -0.64])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 6:

  RA (J2000.0):  118.3078  =  07:53:13.87
  Dec (J2000.0): -5.2740  =  -05:16:26.4
  Error: 6.6 arcsec (radius, 90% conf.)
  Count-rate: (5.0 [+2.4, -1.8])e-3 ct s^-1   
  Distance: 578 arcsec from Swift/BAT-GUANO position.
  Flux: (1.01 [+0.47, -0.37])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/ToO_GRBs/00021530.
This circular is an official product of the Swift-XRT team.

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Jochen Greiner, last update: 25-Oct-2022 [Disclaimer]