//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32816 SUBJECT: GRB 221022A: Fermi GBM Final Real-time Localization DATE: 22/10/22 19:41:48 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM 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 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32824 SUBJECT: GRB 221022A: Swift/BAT-GUANO detection DATE: 22/10/24 02:41:40 GMT FROM: Aaron Tohuvavohu at U Toronto 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/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32833 SUBJECT: GRB 221022A: Swift ToO observations DATE: 22/10/24 19:03:04 GMT FROM: Phil Evans at U of Leicester 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32834 SUBJECT: GRB 221022A: Fermi GBM detection DATE: 22/10/24 21:35:01 GMT FROM: Suraj Poolakkil at UAH 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/" //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32847 SUBJECT: GRB 221022A: Swift-XRT observations DATE: 22/10/25 14:45:14 GMT FROM: Phil Evans at U of Leicester 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.