GRB 220323A
GCN Circular 31782
Subject
GRB 220323A: Fermi GBM Final Real-time Localization
Date
2022-03-23T12:20:36Z (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 SHORT GRB
At 12:10:11 UT on 23 Mar 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220323A (trigger 669730216.566582 / 220323507).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 355.2, Dec = 71.9 (J2000 degrees, equivalent to J2000 23h 40m, 71d 54'), with a statistical uncertainty of 9.9 degrees.
The angle from the Fermi LAT boresight is 25.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220323507/quicklook/glg_skymap_all_bn220323507.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/bn220323507/quicklook/glg_healpix_all_bn220323507.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220323507/quicklook/glg_lc_medres34_bn220323507.gif
GCN Circular 31784
Subject
GRB 220323A: AGILE/MCAL detection
Date
2022-03-23T15:14:50Z (3 years ago)
From
Alessandro Ursi at INAF/IAPS <alessandro.ursi@gmail.com>
A. Ursi (INAF/IAPS), M. Romani (INAF/OA-Brera), C. Pittori, F. Verrecchia
(SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A.
Argan, M. Cardillo, C. Casentini, Y. Evangelista, L. Foffano, E. Menegoni,
G. Piano (INAF/IAPS), F. Lucarelli (SSDC, and INAF/OAR), A. Bulgarelli, A.
Di Piano, 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), A. Giuliani (INAF/IASF-Mi), F.
Longo (Univ. Trieste and INFN Trieste), and P. Tempesta (TeleSpazio),
report on behalf of the AGILE Team:
The AGILE MiniCALorimeter (MCAL; 0.4-100 MeV) detected the short GRB
220323A at T0 = 2022-03-23 12:10:11 (UTC), reported by Fermi GBM (GCN
#31782).
The event lasted 0.35 s and released 295 counts in the detector, above a
background rate of 630 Hz. The time-integrated spectrum of the burst can be
fitted in the energy range 0.4-2 MeV with a power-law with ph.ind = 2.44
(-0.70/+1.13), resulting in a reduced chi-squared of 1.06 (21 d.o.f.) and a
fluence of 5.6e-07 erg/cm^2 (90% confidence level), in the same energy
range. The MCAL light curve can be found at
http://www.agilescienceapp.it/notices/077531_GRB_575122215.552228.png . At
the T0, the event was 134 deg off-axis.
The burst is also clearly visible in the AGILE scientific ratemeters of the
MCAL detector, where it released a total number of 1550 counts (above a
background rate of 1230 Hz). The AGILE MCAL ratemeters light curve can be
found at http://www.agilescienceapp.it/notices/GRB220323A_AGILE_RM.png .
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. Please
note that in the MCAL notice #575122215 the T0 was affected by a temporal
shift of about +4.0 sec due to episodic automated ground software problems
which are then corrected offline.
GCN Circular 31786
Subject
GRB 220323A: AstroSat CZTI detection
Date
2022-03-25T06:39:21Z (3 years ago)
From
Gaurav Waratkar at IIT,Bombay <gauravwaratkar@iitb.ac.in>
R. Gopalakrishnan (IUCAA), V. Prasad (IUCAA), G. Waratkar (IITB), A.
Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (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 detection of a short GRB 220323A which was
also detected by Fermi - GBM (GCN 31782) and AGILE/MCAL (Ursi et al.,
GCN 31784).
The source was clearly detected in the 20-200 keV energy range. The
light curve peaks at 2022-03-23 12:10:10.55 UT. The measured peak count
rate associated with the burst is 1120 (+888, -4) counts/s above the
background in the combined data of three quadrants, with a total of 141
(+48, -50) counts. The local mean background count rate was 386 (+13,
-34) counts/s. Using cumulative rates, we measure a T90 of 0.32 (+0.22,
-0.15) s.
It was also detected in the CsI anticoincidence (Veto) detector in the
100-500 keV energy range.
CZTI GRB detections are reported regularly on the payload site at
http://astrosat.iucaa.in/czti/?q=grb [1]. 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.
Links:
------
[1] http://astrosat.iucaa.in/czti/?q=grb