[vsnet-grb-info 20262] GRB 180112A CALET Gamma-Ray Burst Monitor detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22358
SUBJECT: GRB 180112A CALET Gamma-Ray Burst Monitor detection
DATE:    18/01/17 05:40:23 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto at phys.aoyama.ac.jp>

S. Ozawa (Waseda U), 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. 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 180112A (INTEGRAL SPI-ACS trigger #7990;
Konus-Wind trigger time on 16:29:11.736) triggered the CALET Gamma-ray
Burst Monitor (CGBM) at 16:29:08.39 on 12 January 2018.  The burst signal
was seen by the all CGBM instruments.

The light curve of the SGM shows three isolated episodes.  The first weak
episode peaks around T+2 sec with the duration of 4 sec.  The second
episode has two overlapping pulses, and its emission starts at T+80 sec,
peaks at T+100 sec and ends at T+110 sec.  The third brightest episode
has a single pulse, and its emission starts at T+200 sec, peaks at T+230 sec
and ends at T+250 sec.  The T90 and the T50 durations measured by the
SGM data are 155 +- 80 sec and 134.5 +- 1.2 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1199809543

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