[vsnet-grb-info 18217] SGR 1935+2154: CALET Gamma-Ray Burst Monitor detections

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19665
SUBJECT: SGR 1935+2154: CALET Gamma-Ray Burst Monitor detections
DATE:    16/07/07 04:44:41 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto at phys.aoyama.ac.jp>

Y. Yamada, A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama (AGU),
K. Yamaoka (Nagoya U), S. Nakahira (JAXA), 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), P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The short burst from SGR 1935+2154 (MAXI, Sugita et al. GCN Circ. 19545;
Fermi-GBM trigger #488128598; INTEGRAL-ACS trigger #7490) triggered the CALET
Gamma-Ray Burst Monitor (CGBM) at 15:16:38.82 on 20 June 2016.  The burst signal
was only seen by the SGM instrument.

The light curve of the SGM shows a single peak.  The emission starts at T0-0.2 sec and
ends at T0.  The T90 duration measured by the SGM data is 0.16 +- 0.04 sec (40-100 keV).
The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight/1150470954/

Furthermore, we noticed that the following short bursts from SGR 1935+2154
are also seen in the CGBM survey data.

- 2016-06-02 12:19:30 (Fermi-GBM: bn160602514)
- 2016-06-23 21:19:42 (a possible burst; no confirmation by other instrument)
- 2016-06-23 21:23:36 (Fermi-GBM: bn160623891)
- 2016-06-25 08:04:52 (Fermi-GBM: bn160625337)
- 2016-06-26 09:40:12 (Fermi-GBM: bn160626403)

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