V. Prasad (IUCAA), G. Waratkar (IITB), A. Suresh (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
Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al.,
2021, JApA, 42, 73) showed detection of a long GRB 220128A, which was
also detected by Konus-Wind (Frederiks et al. GCN 31537) with IPN
localization (Kozyrev et al., GCN 31536).
The source was 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 2022-01-28
03:18:22.65 UT. The measured peak count rate is 617 (+71, -81) cts/s
above the background in the combined Veto data of four quadrants, with a
total of 4281 (+424, -589) cts. The local mean background count rate was
1477 (+4, -4) cts/s. We measure a T90 of 26 (+4, -4) 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.