[vsnet-grb-info 19740] GRB 170820A CALET Gamma-Ray Burst Monitor detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21705
SUBJECT: GRB 170820A CALET Gamma-Ray Burst Monitor detection
DATE:    17/08/25 23:59:26 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto at phys.aoyama.ac.jp>

M. L. Cherry (LSU), A. Yoshida, T. Sakamoto, 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), W. Ishizaki (ICRR),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 170820A (Konus-Wind trigger time on 11:12:06.755 UT)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 11:12:05.10 on
20 August 2017.  The burst signal was seen by the all CGBM instruments.

The light curve of the SGM shows a single peak.  The emission starts at
T+1 sec, peaks at T+4.5 sec and ends at T+9 sec.  There is a hint of the
peaked emission at T+8 sec.  The T90 duration measured by the
SGM data is 4.1 +- 0.5 sec (40-1000 keV).

The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight/1187301799/

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