GCN Circular 42659
Subject
LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
Date
2025-11-13T02:29:27Z (2 days ago)
From
Yuta Kawakubo at Aoyama Gakuin University <kawakubo@phys.aoyama.ac.jp>
Via
Web form
H. Hiramatsu, S. Sugita, M. Serino, Y. Kawakubo, Y. Kondo (AGU)
H. Negoro, M. Nakajima, K. Takagi (Nihon U.),
N. Kawai, T. Mihara, (RIKEN),
report on behalf of the MAXI team:
We examined MAXI/GSC all-sky X-ray images (2-20 keV)
after compact binary merger candidate S251112cm at 2025-11-12 15:18:45.362 UTC (GCN #42650).
At the trigger time of S251112cm, the high-voltage of MAXI/GSC was on.
The instantaneous field of view of GSC at the GW trigger time covered 1% of the 90% credible region
of the bayestar 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 bayestar skymap from 15:18:45 to 16:50:09 UTC (T0+0 to T0+5484 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.