[vsnet-grb-info 19519] GRB 170607A CALET Gamma-Ray Burst Monitor detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21259
SUBJECT: GRB 170607A CALET Gamma-Ray Burst Monitor detection
DATE:    17/06/20 00:40:51 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto at phys.aoyama.ac.jp>

S. Nakahira (RIKEN), A. Yoshida, T. Sakamoto, Y. Kawakubo,
M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU),
K. Yamaoka (Nagoya U), I. Takahashi (IPMU), Y. Asaoka, S. Ozawa,
S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR),
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 170607A (D'Ai et al., GCN Circ. 21214;
Hamburg et al., GCN Circ. 21218; INTEGRAL SPI-ACS trigger #7864)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 23:17:56.98
on 7 June 2017.  The burst signal was seen only by the SGM instrument.

The light curve of the SGM shows two distinct peaks.  The first
peak starts at T+2 sec, peaks at T+4 sec and ends at T+8 sec.
The second peak starts at T+210 sec, peaks at T+215 sec and
ends at T+230 sec.  The T90 durations of the first peak and the
second peak measured by the SGM data separately are 4.0 +- 0.5 sec
and 10.5 +- 0.8 sec (40-1000 keV).

The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight/1180912206/

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