GCN Circular 26797
Subject
LIGO/Virgo S200115j: Upper limits from CALET observations.
Date
2020-01-17T10:07:53Z (4 years ago)
From
Yuta Kawakubo at Louisiana State U./CALET <kawakubo1@lsu.edu>
Y. Shimizu (Kanagawa U), A. Yoshida, T. Sakamoto,
V. Pal'shin, S. Sugita (AGU), Y. Kawakubo (LSU),
K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka, S. Torii (Waseda U), T. Tamura (Kanagawa U),
N. Cannady (GSFC/UMBC), M. L. Cherry (LSU),
S. Ricciarini (U of Florence),P. S. Marrocchesi (U of Siena),
and the CALET collaboration:
At the trigger time of the compact binary merger candidate
S200115j T0 = 2020-01-15 04:23:09.742 UT (The LIGO
Scientific Collaboration and Virgo Collaboration, GCN
Circ. 26759), the CALET Gamma-ray Burst Monitor (CGBM)
high voltages were off (from T0-5 min to T0+11 min).
The CALET Calorimeter (CAL) was operating in the high
energy trigger mode at the trigger time of S200115j. Using
the CAL data, we have searched for gamma-ray events in the
10-100 GeV band from -60 sec to +60 sec from the GW trigger
time and found no candidates in the overwrap region with the
LIGO-Virgo high probability localization region. The 90%
upper limit of CAL is 1.7 x 10^-6 erg/cm^2/s (10-100 GeV)
when the summed LIGO-Virgo probability reaches 20%. The CAL
FOV was centered at RA = 84.4 deg, DEC = +45.9 deg at T0.