GCN Circular 33423
Subject
GRB 230304B: CALET Gamma-Ray Burst Monitor detection
Date
2023-03-08T16:07:13Z (a year ago)
From
Yuta Kawakubo at Louisiana State U./CALET <kawakubo1@lsu.edu>
K. Kobayashi (Waseda U), A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC),
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:
The long GRB 230304B (Fermi GBM Final Real-time Localization: Fermi GBM team,
GCN Circ. 33396; AstroSat CZTI detection: Navaneeth et al., GCN Circ 33400)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 14:35:45.442 UTC
on 4 March 2023
(http://cgbm.calet.jp/cgbm_trigger/flight/1361975601/index.html).
The burst signal was seen by only the SGM detector.
The burst light curve shows a multi-peaked structure that starts
at T+3.6 sec, peaks at T+4.1 sec, and ends at T+19.3 sec.
The T90 and T50 durations measured by the SGM data are 14.4 +/- 0.3 sec
and 9.5 +/- 0.3 sec (40-1000 keV), respectively.
The ground-processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1361975601/
The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.