GRB 201009A

A. Ursi (INAF/IAPS), F. Verrecchia, C. Pittori (SSDC, and INAF/OAR), M.
Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), C. Casentini (INAF/IAPS),
A. Argan, M. Cardillo, Y. Evangelista, 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:

A few seconds after emerging from the SAA, the AGILE satellite detected a
burst, with a MCAL trigger at T0 = 2020-10-09 03:08:26 (UT). The event is
visible in the scientific ratemeters of the SuperAGILE (SA; 18-60 keV),
MiniCALorimeter (MCAL; 0.4-100 MeV), and AntiCoincidence (AC; 50-200 keV)
detectors. The event lasted about ~6 s and released 1045 counts in the SA
detector (above a background rate of 74 Hz), 24910 counts in the MCAL
detector (above a background rate of 1176 Hz), and 43490 counts in the AC
detector (above a background rate of 3523 Hz). The AGILE RM light curves
can be found at:
http://www.agilescienceapp.it/notices/GRB201009A_AGILE_RMs.png . The event
could have possibly started earlier, as shown in the SuperAGILE light curve.

The event also triggered a partial high time resolution MCAL data
acquisition.

Additional analysis of AGILE data is in progress.

S. Gupta, V. Sharma A. Vibhute and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed detection of a bright long GRB 201009A, which is also detected by AGILE (Ursi A. et al., GCN #28588
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 ).

The source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-10-09 03:08:21.500 UT. The measured peak count rate associated with the burst is 4215 +/- 69 cts/s above the background in the combined data of four quadrants, with a total of 45310 +/- 77 cts. The local mean background count rate was 516 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 40.20 +/- 0.13 s.  In a preliminary analysis, we find that 3509 Compton events are associated with this event.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-10-09 03:08:21.000 UT. The measured peak count rate is 12953 +/- 121 cts/s above the background in the combined Veto data of four quadrants, with a total of 71480 +/- 124 cts. The local mean background count rate was 1534 +/- 2  cts/s. We measure a T90 of 26.64 +/- 0.12 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, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.