[vsnet-grb-info 24842] LIGO/Virgo S200129m: Upper limits from CALET observations.

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26941
SUBJECT: LIGO/Virgo S200129m: Upper limits from CALET observations.  
DATE:    20/01/30 05:22:04 GMT
FROM:    Yuta Kawakubo at Louisiana State U./CALET  <kawakubo1 at lsu.edu>

M. L. Cherry (LSU), 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), Y. Shimizu, 
T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), 
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 
S200129m T0 = 2020-01-29 06:54:58.435 UT (The LIGO 
Scientific Collaboration and Virgo Collaboration, GCN 
Circ. 26926), the CALET Gamma-ray Burst Monitor (CGBM)
high voltages were off (from T0-31 min to T0+1 min).

The CALET Calorimeter (CAL) was operating in the high 
energy trigger mode at the trigger time of S200129m. 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 5.7 x 10^-5 erg/cm^2/s (10-100 GeV) 
when the summed LIGO-Virgo probability reaches 5%. The CAL 
FOV was centered at RA = 288.7 deg, DEC = -34.3 deg at T0.