GCN Circular 31663
Subject
GRB 220222A: CALET Gamma-Ray Burst Monitor detection
Date
2022-03-02T09:09:24Z (3 years ago)
From
Valentin Pal'shin at AGU <val@phys.aoyama.ac.jp>
S. Ricciarini (U of Florence),
A. Yoshida, T. Sakamoto, V. Pal'shin, 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), P. S. Marrocchesi (U of Siena),
and the CALET collaboration:
The GRB 220222A (Fermi GBM Final Real-time Localization: Fermi GBM team,
GCN Circ. 31630; Swift/BAT-GUANO detection: Tohuvavohu et al., GCN
Circ. 31633; IPN triangulation: Kozyrev et al., GCN Circ. 31649;
Konus-Wind detection: Frederiks et al., GCN Circ. 31657;
https://gcn.gsfc.nasa.gov/other/220222A.gcn3) triggered the CALET Gamma-ray
Burst Monitor (CGBM) at 02:21:16.664 UTC on 22 February 2022
(http://cgbm.calet.jp/cgbm_trigger/flight/1329531683/index.html).
The burst signal was seen only by the SGM detector.
The burst light curve shows a single weak pulse which starts at T+1.3 sec,
peaks at T+2.4 sec,and ends at T+3.0 sec. The T90 and T50 durations
measured by the SGM data are 1.5 +- 0.4 sec and 0.6 +- 0.5 sec
(40-1000 keV), respectively.
The ground processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1329531683/
The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at the Waseda University.