GCN Circular 35811
Subject
GRB 240225B: CALET Gamma-Ray Burst Monitor detection
Date
2024-02-26T22:35:56Z (2 months ago)
From
Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>
Via
Web form
Y. Kawakubo (LSU), A. Yoshida, T. Sakamoto, S. Sugita (AGU),
K. Yamaoka (Nagoya U), S. Nakahira (JAXA),
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 240225B (MAXI/GSC detection: Nakajima et al.,
GCN Circ. 35796; AstroSat CZTI detection: Joshi et al., 35798)
was detected in the ground analysis of the CALET Gamma-ray
Burst Monitor (CGBM) data around 20:12:08.50 on 25 February
2024 (referenced to the AstroSat detection: GCN Circ. 35798)
(http://cgbm.calet.jp/cgbm_trigger/flight/1392926875/index.html).
The main episode that AstroSat CZTI detected was seen by all CGBM
detectors. Also, a hint of emission that MAXI/GSC detected was seen
in the HXM data around T+230 s.
The burst light curve of the main episode shows a multi-peaked
structure that starts at T-7.6 sec, and ends at T+31.1 sec. The T90
and T50 durations measured by the SGM data are 33.0 +/- 0.9 sec
and 17.1 +/- 1.3 sec (40-1000 keV), respectively.
The ground-processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1392926875/index.html
The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.