[vsnet-grb-info 17394] GRB 151227B: CALET Gamma-Ray Burst Monitor detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18792
SUBJECT: GRB 151227B: CALET Gamma-Ray Burst Monitor detection
DATE:    15/12/31 22:37:10 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto at phys.aoyama.ac.jp>

K. Senuma, A. Yoshida, T. Sakamoto, I. Takahashi, Y. Kawakubo, 
M. Moriyama, Y. Yamada (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), 
Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), 
M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena) 
and the CALET collaboration:

The long-duration GRB 151227B (Toelge et al. GCN Circ. 18727; Hurley et al. GCN Circ. 18773; 
Golenetskii et al. GCN Circ. 18781) triggered the CALET Gamma-Ray Burst Monitor (CGBM) at 
5:13:49.89 UT on 27 December 2015.  The clear burst signal was detected by HXM1 and SGM 
instruments.  

The light curve of the SGM shows three main peaks.  The first peak starts at T0, 
peaks at T0+2 sec and ends at T0+4 sec.  The brightest second peak, which consists 
of various sub-peaks, starts at T0+20 sec, peaks at T0+31 sec and ends at T0+40 sec.  
The third peak starts at T0+40 sec, peaks at T0+45 sec and ends at T0+50 sec.  
The T90 duration measured by the SGM data is 42.0 +- 0.3 sec (40-1000 keV).  

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