[vsnet-grb-info 20208] GRB 171229A CALET Gamma-Ray Burst Monitor detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22304
SUBJECT: GRB 171229A CALET Gamma-Ray Burst Monitor detection
DATE:    18/01/06 12:56:48 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto at phys.aoyama.ac.jp>

S. Nakahira (RIKEN), A. Yoshida, T. Sakamoto, V. Pal'shin,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 171229A (Konus-Wind trigger time on 09:59:28.212)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 09:59:37.40 on
29 December 2017.  This GRB is also clearly seen by the publicly available
INTEGRAL SPI-ACS light curve.  The burst signal was seen only by the SGM
instrument.

The light curve of the SGM shows a single pulse followed by a weak extended
emission.  The emission starts at T-10 sec, peaks at T0 and ends at T+67 sec.
The T90 duration measured by the SGM data is 70.8 +- 6.9 sec (40-1000 keV).
The T50 duration measured by the SGM data is 38.1 +- 17.7 sec (40-1000 keV).

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1198576596/

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