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GCN Circular 20513

LIGO/Virgo G270580: CALET Observations
2017-01-24T12:55:12Z (7 years ago)
Takanori Sakamoto at Aoyama Gakuin U <>
Y. Kawakubo, A. Yoshida, T. Sakamoto, M. Moriyama, Y. Yamada (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 CALET Gamma-ray Burst Monitor (CGBM) was operating at the trigger time
of G270580 (GCN Circ. 20486).  No CGBM on-board trigger occurred at the time
of the event.  Based on the LIGO localization sky map (LIB_skymap.fits.gz),
the southern arc of the high probability area was in the field-of-view of CGBM.
The summed LIGO probabilities inside the HXM and the SGM field of view
are 24% and 33%.

Based on the analysis of the light curve data with 0.125 sec time resolution
from -60 sec to 60 sec from the trigger time, we found no significant excess
around the trigger time in either the HXM (7-1000 keV) or the SGM (0.1-20 MeV)

The CALET Calorimeter (CAL) was operating in high energy trigger mode at the trigger
time of G270580.  Using CAL data, we have searched for gamma-ray events above
10 GeV from -60 sec to +60 sec from the GW trigger time and found no candidates.
The summed LIGO probabilities inside the CAL field of view is ~4%.
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