GRB 221022A
GCN Circular 32816
Subject
GRB 221022A: Fermi GBM Final Real-time Localization
Date
2022-10-22T19:41:48Z (3 years ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
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
Subject
GRB 221022A: Swift/BAT-GUANO detection
Date
2022-10-24T02:41:40Z (3 years ago)
From
Aaron Tohuvavohu at U Toronto <aaron.tohu@gmail.com>
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
Subject
GRB 221022A: Swift ToO observations
Date
2022-10-24T19:03:04Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
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
Subject
GRB 221022A: Fermi GBM detection
Date
2022-10-24T21:35:01Z (3 years ago)
From
Suraj Poolakkil at UAH <sp0076@uah.edu>
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
Subject
GRB 221022A: Swift-XRT observations
Date
2022-10-25T14:45:14Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
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.