//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32820 SUBJECT: GRB 221022B: Fermi GBM Final Real-time Localization DATE: 22/10/22 23:05:54 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 22:55:48 UT on 22 Oct 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 221022B (trigger 688172153.911872 / 221022955). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 167.4, Dec = 15.4 (J2000 degrees, equivalent to J2000 11h 09m, 15d 24'), with a statistical uncertainty of 1.8 degrees. The angle from the Fermi LAT boresight is 93.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221022955/quicklook/glg_skymap_all_bn221022955.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/bn221022955/quicklook/glg_healpix_all_bn221022955.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221022955/quicklook/glg_lc_medres34_bn221022955.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32822 SUBJECT: GRB 221022B: AGILE detection DATE: 22/10/23 08:27:48 GMT FROM: Alessandro Ursi at INAF/IAPS C. Casentini, A. Ursi (INAF/IAPS), F. Verrecchia (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), C. Pittori (SSDC, and INAF/OAR), A. Argan, M. Cardillo, Y. Evangelista, L. Foffano, E. Menegoni, G. Piano (INAF/IAPS), F. Lucarelli (SSDC, and INAF/OAR), A. Bulgarelli, V. Fioretti, F. Fuschino, N. Parmiggiani (INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ. Trieste and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of the AGILE Team: The AGILE satellite detected the GRB 221022B at T0 = 2022-10-22 22:56:11.76 +/- 0.01 s (UTC), reported by Fermi GBM (#GCN 32820, trigger no. 688172153). The burst is clearly visible in the AGILE scientific ratemeters of the MiniCALorimeter (MCAL; 0.4-100 MeV), and AntiCoincidence (AC; 50-200 keV) detectors. The event lasted about 15 s and it released a total number of 27380 counts in the MCAL detector (above a background rate of 1070 Hz), and 80780 counts in the AC detector (above a background rate of 2760 Hz). The AGILE ratemeter light curves can be found at http://www.agilescienceapp.it/notices/GRB221022B_AGILE_RM.png . The event also triggered a partial high time resolution MCAL data acquisition, covering the onset of the first episode, from T0-33.15 s to T0+1.70 s, and released a total number of ~830 counts in the detector, above an average background rate of 588 Hz. The MCAL light curve can be found at http://www.agilescienceapp.it/notices/080607_GRB_MCAL_593564171.767936.png . The AGILE-MCAL detector is a CsI detector with a 4 pi FoV, sensitive in the energy range 0.4-100 MeV. Additional analysis of AGILE data is in progress. Automatic MCAL GRB alert Notices can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32823 SUBJECT: GRB 221022B: Swift/BAT-GUANO detection outside the coded FOV DATE: 22/10/24 00:22:00 GMT FROM: Aaron Tohuvavohu at U Toronto Gayathri Raman (PSU), Aaron Tohuvavohu (U Toronto), James DeLaunay (UAlabama), Jamie A. Kennea (PSU), Tyler Parsotan (GSFC/UMBC) report: Swift/BAT did not localize GRB 221022B onboard (T0: 2022-10-22T22:55:48 UTC, Fermi/GBM GCN 32820, AGILE GCN 32822). 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 by this notice, 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 44.9 in a 16.384 s analysis time bin. NITRATES results are consistent with a burst coming from outside the FOV, with DeltaLLHOut of -17. The best fit sky location is consistent with the Fermi/GBM position (GCN 32820). 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: 32830 SUBJECT: GRB 221022B: Fermi GBM detection DATE: 22/10/24 17:28:04 GMT FROM: Suraj Poolakkil at UAH S. Poolakkil (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 22:55:48.91 UT on 22 October 2022, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 221022B (trigger 688172153 / 221022955, GCN 32820) which was also detected by the Swift/BAT- GUANO (Raman et al. 2022, GCN 32823). The angle from the Fermi LAT boresight at the GBM trigger time is 93 degrees. The GBM light curve consists of a single peak followed by some extended emission with a duration (T90) of about 32 s (50-300 keV). The time-averaged spectrum from T0+7.17 s to T+46.08 s is best fit by Band function, with Epeak = 265 +/- 6 keV, alpha = -0.61 +/- 0.02 and beta = -2.61 +/- 0.10. The event fluence (10-1000 keV) in this time interval is (7.14 +/- 0.07)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+22.3 s in the 10-1000 keV band is 34.3 +/- 0.5 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: 32837 SUBJECT: GRB 221022B: AstroSat CZTI detection DATE: 22/10/25 01:57:14 GMT FROM: Gaurav Waratkar at IIT,Bombay R. Gopalakrishnan (IUCAA), V. Prasad (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 GRB 221022B which was also detected by Fermi GBM (GCN 32820), AGILE (Casentini et al., GCN 32822) and Swift/BAT-GUANO (Gayathri et al., GCN 32823). The source was clearly detected in the 20-200 keV energy range. The light curve peaks at 2022-10-22 22:56:11.50 UTC. The measured peak count rate associated with the burst is 1613 (+72, -78) counts/s above the background in the combined data of all quadrants, with a total of 14862 (+774, -850) counts. The local mean background count rate was 494 (+2, -3) counts/s. Using cumulative rates, we measure a T90 of 31 (+5, -4) s. It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2022-10-22 22:56:10.86 UTC. The measured peak count rate is 2187 (+97, -105) counts/s above the background in the combined Veto data of all quadrants, with a total of 18217 (+1046, -1027) counts. The local mean background count rate was 1575 (+3, -4) counts/s. We measure a T90 of 27 (+4, -6) 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32842 SUBJECT: IPN triangulation of GRB 221022B (long) DATE: 22/10/25 11:38:41 GMT FROM: Anna Ridnaia at Ioffe Institute 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 221022B (Fermi/GBM detection: Fermi GBM team, GCN 32820; Poolakkil & Meegan, GCN 32830; AGILE detection: Casentini et al., GCN 32822; Swift/BAT-GUANO detection: Raman et al., GCN 32823; AstroSat CZTI detection: Gopalakrishnan et al., GCN 32837) has been detected by Fermi (GBM), INTEGRAL (SPI-ACS), Konus-Wind, AGILE (MCAL, AC), AstroSat (CZTI) and Swift (BAT), so far, at about 82549 s UT (22:55:49). 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: 170.477 (11h 21m 55s) +18.413 (+18d 24' 46") Corners: 179.823 (11h 59m 18s) +26.613 (+26d 36' 46") 161.965 (10h 47m 52s) +10.411 (+10d 24' 38") 164.336 (10h 57m 21s) +9.908 ( +9d 54' 28") 183.830 (12h 15m 19s) +26.171 (+26d 10' 14") --------------------------------------------- The error box area is 52.5 sq. deg, and its maximum dimension is 26.0 deg (the minimum one is 2.2 deg). The Sun distance was 43 deg. This box may be improved. The IPN localization is consistent with, but reduces the area of, the Fermi-GBM final localization (GCN 32820). A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB221022_T82557/IPN The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32844 SUBJECT: GRB 221022B: Detection by GRBAlpha DATE: 22/10/25 12:53:55 GMT FROM: Marianna Dafcikova at Masaryk University <500025@mail.muni.cz> M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), F. Munz, N. Husarikova, J.-P. Breuer, M. Topinka, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropo litan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration. The long-duration GRB 221022B (Fermi/GBM detection: GCN Circ. 32820; AGILE/MCAL detection: Casentini et al., GCN Circ. 32822; Swift/BAT detection: Raman et al., GCN Circ. 32823; ASTROSAT/CZTI detection: Gopalakrishnan et al. GCN Circ. 32837; Konus/Wind trigger at 2022-10-22 22:55:57 UT; INTEGRAL/SPI-ACS detection at 2022-10-22 22:56:13 UT) was detected by the GRBAlpha 1U CubeSat (Pal et al. Proc. SPIE 2020). The 23 sigma detection was confirmed at the peak time 2022-10-22 22:56:11.8 UTC. The GRB has a T90 duration of 32 s. The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB221022B_GCN.pdf GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). Its detector consists of a 75 x 75 x 5 mm^3 CsI(Tl) scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, we are continuously upgrading the on-board data acquisition software stack. The ground segment is also supported by the radio amateur community, and it takes advantage of the SatNOGS network for increased data downlink volume. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32864 SUBJECT: Konus-Wind detection of GRB 221022B DATE: 22/10/27 12:40:54 GMT FROM: Anna Ridnaia at Ioffe Institute A.Ridnaia, D. Frederiks, A.Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The long-duration GRB 221022B (Fermi/GBM detection: Fermi GBM team, GCN 32820; Poolakkil & Meegan, GCN 32830; AGILE detection: Casentini et al., GCN 32822; Swift/BAT-GUANO detection: Raman et al., GCN 32823; AstroSat CZTI detection: Gopalakrishnan et al., GCN 32837; IPN triangulation: Ridnaia et al., GCN 32842; GRBAlpha detection: Dafcikova et al., GCN 32844) triggered Konus-Wind at T0=82557.097 s UT (22:55:57.097). The burst light curve shows a multipeaked structure which starts at ~T0-12.1 s and has a total duration of ~51.9 s. The emission is seen up to ~4 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB221022_T82557/ As observed by Konus-Wind, the burst had a fluence of 8.19(-0.62,+0.67)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+11.984 s, of 1.57(-0.24,+0.24)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0+8.448 to T0+43.776 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.68(-0.11,+0.12), the high energy photon index beta = -2.69(-0.42,+0.23), the peak energy Ep = 268(-21,+23) keV (chi2 = 114/98 dof). The spectrum near the maximum count rate (measured from T0+8.448 to T0+12.800 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.30(-0.13,+0.15), the high energy photon index beta = -2.60(-0.24,+0.17), the peak energy Ep = 299(-24,+27) keV (chi2 = 104/78 dof). All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.