GCN Circular 34304
Subject
LIGO/Virgo/KAGRA S230731an: Coverage and upper limits from MAXI/GSC observations
Date
2023-07-31T23:47:05Z (a year ago)
From
Satoshi Sugita at Aoyama Gakuin U. <sugita@phys.aoyama.ac.jp>
Via
email
M. Nakajima, H. Negoro, (Nihon U.),
T. Mihara, N. Kawai (RIKEN),
S. Sugita, M. Serino, H. Hiramatsu, H. Nishikawa, Y. Kondo (AGU),
Y. Kawakubo (LSU)
report on behalf of the MAXI team:
We examined MAXI/GSC all-sky X-ray images (2-20 keV)
after compact binary merger candidate S230731an at 2023-07-31 21:53:07
UTC (GCN 34303).
At the trigger time of S230731an, the high-voltage of MAXI/GSC was off,
and it was turned on at T0+628 sec (+10.5 min).
The first one-orbit (92 min) scan observation with GSC after the event
covered 95%
of the 90% credible region of the bayestar skymap from 22:03:35 to
23:07:43 UTC (T0+628 to T0+4476 sec).
No significant new source was found in the region in the one-orbit
scan observation.
A typical 1-sigma averaged upper limit obtained in one scan observation
is 20 mCrab at 2-20 keV.