GCN Circular 18724
Subject
GRB 151225A: CALET Gamma-Ray Burst Monitor detection of a possible short GRB
Date
2015-12-26T02:37:37Z (9 years ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
Y. Kawakubo, A. Yoshida, T. Sakamoto, I. Takahashi, K. Senuma,
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:
A possible short-duration GRB 151225A (trigger #1135105601) triggered the CALET
Gamma-Ray Burst Monitor (CGBM) at 19:09:10.34 UT on 25 December 2015. The clear
burst signal was detected by all three CGBM instruments.
The light curve of the SGM shows a double peak structure. The initial spike
starts and peaks around T0. The second peak starts around T0+0.5 sec, peaks
around T0+0.7 sec and ending around T0+1.5 sec. Above 500 keV band, the first
peak looks insignificant, instead the 2nd peak is clearly visible. Based on the
light curve inspection, the signal is clearly visible up to ~1.5 MeV. Low energy
data show no significant soft extended emission above ~7 keV. The T90 duration
measured by the SGM data is 1.87 +- 0.13 sec (40-450 keV).
Identification of this possible short event by other spacecraft is strongly encouraged.