P K. Navaneeth (IUCAA), R. Gopalakrishnan (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 short GRB 230129A which was
also detected by Fermi GBM (GCN Circ. 33232).
The source was faintly detected in the 20-200 keV energy range. The
light curve peaks at 2023-01-29 06:05:21.15 UTC. The measured peak count
rate associated with the burst is 300 (+148, -38) counts/s above the
background in the combined data of all quadrants, with a total of 161
(+48, -54) counts. The local mean background count rate was 319 (+7,
-12) counts/s. Using cumulative rates, we measure a T90 of 0.78 (+0.37,
-0.36) s. We note that the T90 measurement may be a slight underestimate
due to the limited number of photons detected from the burst.
It was also clearly 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. 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.