Skip to main content
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. See news and announcements

GCN Circular 30782

GRB 210905A: AstroSat CZTI detection
2021-09-07T15:35:29Z (3 years ago)
Gaurav Waratkar at IIT,Bombay <>
V. Prasad (IUCAA), P. Sawant (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 long GRB 210905A, which was
also detected by Swift-BAT (Sonbas et al., GCN 30765) and a
sub-threshold detection in Fermi-GBM (Veres & Roberts, GCN 30779).

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
2021-09-05 00:12:40.5 UT. The measured peak count rate associated with
the burst is 87 (+37.9, -7) cts/s above the background in the combined
data of two quadrants (out of four), with a total of 1092 (+250, -294)
cts. The local mean background count rate was 286.0 (+2, -2) cts/s.
Using cumulative rates, we measure a T90 of 24 (+11, -7) s.

CZTI GRB detections are reported regularly on the payload site at [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. 

Looking for U.S. government information and services? Visit