//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31672 SUBJECT: GRB 220304A: Fermi GBM Final Real-time Localization DATE: 22/03/04 05:39:15 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 05:28:58 UT on 4 Mar 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220304A (trigger 668064543.786552 / 220304228). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 245.0, Dec = -35.7 (J2000 degrees, equivalent to J2000 16h 19m, -35d 42'), with a statistical uncertainty of 1.0 degrees. The angle from the Fermi LAT boresight is 145.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220304228/quicklook/glg_skymap_all_bn220304228.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/bn220304228/quicklook/glg_healpix_all_bn220304228.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220304228/quicklook/glg_lc_medres34_bn220304228.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31674 SUBJECT: GRB 220304A: BALROG localization (Fermi Trigger / GRB 220304228) DATE: 22/03/04 07:33:33 GMT FROM: Jochen Greiner at MPE,Garching B. Biltzinger, F. Kunzweiler, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report: The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger at 05:28:58 on 04 March 2022 were automatically fitted for spectrum and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427; Berlato et al. 2019, ApJ 873, 60). The best-fit position (1 sigma statistical errors) is: RA(2000.0) = 249.0+/-0.6 deg Decl.(2000.0) = -37.9+/-0.3 deg We estimate an additional systematic error of 1 deg. Further details are available at: https://grb.mpe.mpg.de/grb/GRB220304228/ The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB220304228/healpix The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB220304228/json //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31676 SUBJECT: Fermi GRB 220304A: Global MASTER-Net observations report DATE: 22/03/04 08:30:14 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, T.Pogrosheva, E.Minkina, A.Chasovnikov, V.Topolev, V.Grinshpun, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev (Irkutsk State University, API), B.L.Carrasco, J.R.Valdes,V.Chavushyan, C.J.Martinez, V.M.Patino Alvarez, M.L.H.Rodriguez (INAOE, OAGH) A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-IAC robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Spain (IAC Teide Observatory) started inspect of the Fermi GRB 220304A ( Fermi GBM team, GCN 31672) errorbox 141 sec after notice time and 148 sec after trigger time at 2022-03-04 05:31:27 UT, with upper limit up to 17.7 mag. The observations began at zenith distance = 65 deg. The sun altitude is -25.8 deg. The galactic latitude b = 10 deg., longitude l = 344 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1901611 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 164 | 2022-03-04 05:31:27 | MASTER-IAC | (16h 31m 09.59s , -34d 58m 25.0s) | P| | 30 | 16.7 | 164 | 2022-03-04 05:31:27 | MASTER-IAC | (16h 32m 18.05s , -35d 06m 08.0s) | P- | 30 | 16.1 | 287 | 2022-03-04 05:33:20 | MASTER-IAC | (16h 31m 06.66s , -34d 57m 41.0s) | P| | 50 | 17.0 | 287 | 2022-03-04 05:33:20 | MASTER-IAC | (16h 32m 15.15s , -35d 05m 23.2s) | P- | 50 | 16.7 | 367 | 2022-03-04 05:34:30 | MASTER-IAC | (16h 31m 07.06s , -34d 56m 42.3s) | P| | 70 | 17.1 | 367 | 2022-03-04 05:34:30 | MASTER-IAC | (16h 32m 15.46s , -35d 04m 24.5s) | P- | 70 | 16.9 | 462 | 2022-03-04 05:36:00 | MASTER-IAC | (16h 31m 12.49s , -34d 57m 44.8s) | P| | 80 | 17.2 | 462 | 2022-03-04 05:36:00 | MASTER-IAC | (16h 32m 20.78s , -35d 05m 26.9s) | P- | 80 | 16.9 | 571 | 2022-03-04 05:37:40 | MASTER-IAC | (16h 31m 06.38s , -34d 58m 46.1s) | P| | 100 | 17.3 | 571 | 2022-03-04 05:37:40 | MASTER-IAC | (16h 32m 14.60s , -35d 06m 28.1s) | P- | 100 | 17.0 | 706 | 2022-03-04 05:39:40 | MASTER-IAC | (16h 17m 26.64s , -35d 37m 37.7s) | P| | 130 | 17.6 | 706 | 2022-03-04 05:39:40 | MASTER-IAC | (16h 18m 35.17s , -35d 45m 20.1s) | P- | 130 | 17.4 | 872 | 2022-03-04 05:42:10 | MASTER-IAC | (16h 17m 23.11s , -35d 36m 33.5s) | P| | 160 | 17.6 | 872 | 2022-03-04 05:42:10 | MASTER-IAC | (16h 18m 31.47s , -35d 44m 16.5s) | P- | 160 | 17.5 | 2103 | 2022-03-04 06:03:31 | MASTER-IAC | (16h 15m 06.77s , -34d 47m 40.2s) | C | 60 | 17.5 | 2103 | 2022-03-04 06:03:31 | MASTER-IAC | (16h 25m 04.10s , -34d 54m 02.7s) | C | 60 | 17.3 | 2183 | 2022-03-04 06:04:51 | MASTER-IAC | (16h 30m 06.12s , -36d 49m 14.5s) | C | 60 | 17.3 | 2183 | 2022-03-04 06:04:51 | MASTER-IAC | (16h 19m 54.38s , -36d 42m 50.0s) | C | 60 | 17.7 | 2263 | 2022-03-04 06:06:11 | MASTER-IAC | (16h 21m 25.45s , -33d 02m 05.6s) | C | 60 | 17.4 | 2422 | 2022-03-04 06:08:51 | MASTER-IAC | (16h 06m 35.72s , -34d 53m 49.9s) | C | 60 | 17.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31677 SUBJECT: GRB 220304A: Swift/BAT-GUANO detection outside the coded FOV DATE: 22/03/04 16:15:57 GMT FROM: Aaron Tohuvavohu at U Toronto James DeLaunay (UAlabama), Aaron Tohuvavohu (U Toronto), Gayathri Raman (PSU), Jamie A. Kennea (PSU), report: Swift/BAT did not localize GRB 220304A onboard (T0: 2022-03-04T05:28:58 UTC, Fermi/GBM GCN 31672). 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 49 in a 16.384 s analysis time bin, the longest time bin of the search. The duration of the burst is at least 30 seconds. NITRATES results indicate a burst coming from outside the coded FOV, with DeltaLLHOut of -55. The best fit location is consistent with the Fermi/GBM RoboBA (GCN 31672), and BALROG (GCN 31674) localizations. 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: 31710 SUBJECT: GRB 220304A Fermi GBM detection DATE: 22/03/08 16:11:39 GMT FROM: Boyan A. Hristov at UAH Boyan A. Hristov (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 05:28:58.79 UT on 04 March 2022, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 220304A (trigger 668064543 / 220304228, GCN 31672), which was also detected by the Swift/BAT-GUANO (DeLaunay et al. 2022, GCN 31677). The GBM light curve consists of a single spike with a duration (T90) of about 32 s (50-300 keV). The time-averaged spectrum from T0+3.072 s to T0+35.841 s is best fit by a Band function with Epeak = 90 +/- 2 keV, alpha = -0.24 +/- 0.06, and beta = -3.2 +/- 0.1. The event fluence (10-1000 keV) in this time interval is (59 +/- 0.7)E-6 erg/cm^2. The 1-sec peak photon flux measured starting from T0+15.488 s in the 10-1000 keV band is 36 +/- 1 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/"