GCN Circular 36475

J. Joshi (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 long-duration GRB 240514D. Inspection of INTEGRAL/SPI-ACS data also showed the detection of the burst.

The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2024-05-14 00:43:13.50 UTC. The measured peak count rate associated with the burst is 146 (+35, -35) counts/s above the background in the combined data of all quadrants, with a total of 507 (+127, -137) counts. The local mean background count rate was 312 (+3, -4) counts/s. Using cumulative rates, we measure a T90 of 5.8 (+1.5, -2.1) s.

The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2024-05-14 00:43:11.64 UTC. The measured peak count rate associated with the burst is 980 (+79, -82) counts/s above the background in the combined data of all quadrants, with a total of 3424 (+256, -276) counts. The local mean background count rate was 1302 (+6, -7) counts/s. We measure a T90 of 5.6 (+1.0, -0.4) s from the cumulative Veto light curve.

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.

CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb