GCN Circular 41623
Subject
LIGO/Virgo/KAGRA S250831cc: Coverage and upper limits from MAXI/GSC observations
Date
2025-09-01T03:03:21Z (a month ago)
From
Hitoshi Negoro at Nihon University/MAXI team <negoro.hitoshi@nihon-u.ac.jp>
Via
Web form
H. Negoro, M. Nakajima, K. Takagi (Nihon U.),
N. Kawai, T. Mihara, (RIKEN),
S. Sugita, M. Serino, Y. Kawakubo, H. Hiramatsu, Y. Kondo (AGU)
report on behalf of the MAXI team:
We examined MAXI/GSC all-sky X-ray images (2-20 keV)
after compact binary merger candidate S250831cc at 2025-08-31 12:30:48.228 UTC.
At the trigger time of S250831cc, the high-voltage of MAXI/GSC was on,
but the FOV was out of the 90% credible region of the bayestar skymap.
The first one-orbit (92 min) scan observation with GSC after the event covered 48%
of the 90% credible region of the bayestar skymap from 13:12:46 to 13:24:01 UTC
(T0+2518 to T0+3193 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.
If you require information about X-ray flux by MAXI/GSC at specific coordinates,
please contact the submitter of this circular by email.