GCN Circular 32541
Subject
GRB 220910A: AstroSat CZTI detection
Date
2022-09-10T19:34:14Z (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 (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 bright long GRB 220910A
which was also detected by AGILE (Ursi et al., GCN 32540) and reported
in an IPN_RAW notice (by Konus-Wind).
The source was clearly detected in the 20-200 keV energy range. The
light curve showed multiple peaks of emission with the strongest peak at
2022-09-10 05:48:29.0 UTC. The measured peak count rate associated with
the burst is 4111 (+341, -343) counts/s above the background in the
combined data of all quadrants, with a total of 5809 (+205, -203)
counts. The local mean background count rate was 503 (+6, -11) counts/s.
Using cumulative rates, we measure a T90 of 2.6 (+0.4, -0.3) s.
It was also clearly detected in the CsI anticoincidence (Veto) detector
in the 100-500 keV energy range. The light curve peaks at 2022-09-10
05:48:27.0 UTC. The measured peak count rate is 6301 (+143, -155)
counts/s above the background in the combined Veto data of all
quadrants, with a total of 14603 (+414, -431) counts. The local mean
background count rate was 1477 (+7, -8) counts/s. We measure a T90 of
3.7 (+0.5, -0.6) 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.