GCN Circular 36850

LIGO/Virgo/KAGRA S240711cm: Coverage and upper limits from MAXI/GSC observations

T. Mihara, N. Kawai (RIKEN),
H. Negoro, M. Nakajima, K. Takagi (Nihon U.),
S. Sugita, M. Serino, Y. Kawakubo, H. Hiramatsu, H. Nishikawa, 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 S240711cm at 2024-07-11 20:11:09.984 UTC.

At the trigger time of S240711cm, the high-voltage of MAXI/GSC was on.
The instantaneous field of view of GSC at the GW trigger time covered 2% of the 90% credible region
of the cwb sky map, in which we found no significant new X-ray source.
The first one-orbit (92 min) scan observation with GSC after the event covered 72%
of the 90% credible region of the cwb skymap from 20:11:09 to 21:40:42 UTC (T0+0 to T0+5373 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.