GCN Circular 33657
Subject
GRB 230418A: AstroSat CZTI detection
Date
2023-04-20T05:59:08Z (a year ago)
From
Gaurav Waratkar at IIT,Bombay <gauravwaratkar@iitb.ac.in>
P K. Navaneeth (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 short GRB 230418A which was also detected by Fermi (O.J. Roberts, et al., GCN Circ. 33652), Swift/BAT-GUANO (S. Ronchini, et al., GCN Circ. 33653), and AGILE (G. Panebianco, et al., GCN Circ. 33656).
The source was clearly detected in the 20-200 keV energy range. The light curve peaks at 2023-04-18 21:11:33.56 UTC. The measured peak count rate associated with the burst is 2120 (+893, -443) counts/s above the background in the combined data of all quadrants, with a total of 155 (+52, -45) counts. The local mean background count rate was 488 (+18, -38) counts/s. Using cumulative rates, we measure a T90 of 0.20 (+0.16, -0.06) s.
The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.
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