Difference: GCNCIRCULAR21706 ( vs. 1)

Y. Asaoka (Waseda U), A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), I. Takahashi (IPMU), S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU), S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena) and the CALET collaboration:

The CALET Gamma-ray Burst Monitor (CGBM) was operating at the trigger time of G298936 (The LIGO Scientific Collaboration and Virgo Collaboration, GCN Circ. 21656). No CGBM on-board trigger occurred at the time of the event. Based on the LIGO-Virgo localization sky map (bayestar-HLV.fits.gz), the part of the northern 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 57% and 66%.

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 (7-3000 keV) or the SGM (40 keV -28 MeV) data.

The CALET Calorimeter (CAL) was operating in high energy trigger mode at the trigger time of G298936. Similar to CGBM, the northern arc of the high probability area of the LIGO-Virgo localization map was in the field of view of CAL. Using 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. The 90% upper limit of CAL is 2e-5 erg/cm2/s (10-100 GeV) when the summed LIGO-Virgo probabilities reaches at 20%.

-- DeepChatterjee - 25 Aug 2017