[vsnet-grb-info 20329] GRB 180218A CALET Gamma-Ray Burst Monitor detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22425
SUBJECT: GRB 180218A CALET Gamma-Ray Burst Monitor detection
DATE:    18/02/20 06:02:34 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto at phys.aoyama.ac.jp>

W. Ishizaki (ICRR), A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo,
M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU),
K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), I. Takahashi (IPMU),
Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu,
T. Tamura (Kanagawa U), M. L. Cherry (LSU), S. Ricciarini (U of Florence),
A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The bright GRB 180218A (Svinkin et al., GCN circ. 22423;
Poolakkil et al., GCN circ. 22424) triggered the CALET Gamma-ray
Burst Monitor (CGBM) at 15:14:05.326 UTC on 18 February 2018.
The burst signal was seen by all CGBM detectors.

The burst light curve shows a single multi-peaked pulse which starts at
T+0.5 sec, peaks at T+4.6 sec and ends at T+8.5 sec.  The T90 and the
T50 durations measured by the SGM data are 4.75 +- 1.27 sec and
1.88  +- 0.13 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1203001776/

The CALET data used in this analysis are provided by the Waseda CALET
Operation Center located at the Waseda University.