GCN Circular 24548

T. Sakamoto, A. Yoshida, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), 
S. Nakahira (RIKEN),  Y. Asaoka, S. Ozawa,
S. Torii (Waseda U), Y. Shimizu, 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:

The CALET Gamma-ray Burst Monitor (CGBM) was operating at the 
trigger time of S190513bm T0 = 2019-05-13 20:54:28.747 UT (The LIGO
Scientific Collaboration and Virgo Collaboration, GCN Circ. 24522
Not found
 
 
). 

No CGBM on-board trigger occurred around the event time.  Based 
on the LIGO-Virgo localization sky map, most of the part of the high
probability area was inside of the field-of-view of SGM.  The summed 
LIGO probabilities inside the HXM and the SGM field of view are 33%
and 95% (and 0% credible region of the initial localization map were 
Earth-occulted).  The HXM and SGM field of views were centered at
RA = 355.5 deg, Dec=11.0 deg and RA = 348.0 deg, Dec = 4.3 deg at 
T0.

Based on the analysis of the light curve data with 0.125 sec time 
resolution from T0-60 sec to T0+60 sec, we found no significant excess 
(signal-to-noise ratio >= 7) around the trigger time in either the HXM 
(7-3000 keV) or the SGM (40 keV -28 MeV) data. 

The CALET Calorimeter (CAL) was operating in low energy trigger mode
at the trigger time of S190513bm.  Using CAL data, we have searched for
gamma-ray events in the 1-10 GeV band from -60 sec to +60 sec
from the GW trigger time and found no candidates.

The 90% upper limit of CAL is 6.0x10^-5 erg/cm2/s (1-10 GeV) when
the summed LIGO-Virgo probability reaches 5%.  The CAL FOV was 
centered at RA = 348.0 deg, Dec = 4.4 deg at T0.