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GCN Circular 29383

Subject
Recent activity of SGR 1935+2154 as observed by CGBM
Date
2021-02-03T00:27:16Z (3 years ago)
From
Valentin Pal'shin at AGU <val@phys.aoyama.ac.jp>
S. Ricciarini (U of Florence),
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC),
M. L. Cherry (LSU), P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

During the recent reactivation of SGR 1935+2154 reported by
GECAM (Huang et al., GCN Circ. 29363; Wang et al. GCN Circ. 29377),
IPN (Ridania et al., GCN Circ. 29365), Konus-Wind (Ridnaia et al.,
GCN Circ. 29373), Fermi-GBM (Roberts et al., GCN Circ. 29374, ATel #14359),
and INTEGRAL-IBAS (Mereghetti et al., GCN Circ. 29381)
the CALET Gamma-ray Burst Monitor (CGBM) has triggered on three bright
short soft bursts from this SGR (alerted triggers 1295912101, 1295951738,
and 1296063650).
Additional five weaker short soft bursts observed in the waiting mode
(125-ms time resolution, 8 energy channels) with high S/N were also likely
originated from SGR 1935+2154.

The following table summarizes the bursts:

       Time, UTC           Mode     Other reported detections
-------------------------------------------------------------
2021-01-28 23:35:02.450   Trig         Fermi-GBM
2021-01-29 02:46:23       BG           Fermi-GBM
2021-01-29 10:35:39.707   Trig         Fermi-GBM
2021-01-29 15:23:30       BG           -
2021-01-29 21:15:56       BG           Fermi-GBM
2021-01-30 13:05:39       BG           -
2021-01-30 17:40:54.610   Trig         GECAM
2021-01-31 03:01:28       BG           -
--------------------------------------------------------------

At the listed times, SGR 1935+2154 was in the FOVs of the CGBM detectors.

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