GCN Circular 40937
Subject
LIGO/Virgo/KAGRA S250704ab: Coverage and upper limits from MAXI/GSC observations
Date
2025-07-04T06:49:21Z (a day ago)
From
Yuta Kawakubo at Aoyama Gakuin University <kawakubo@phys.aoyama.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 S250704ab at 2025-07-04 04:30:48.040 UTC (GCN #40935).
At the trigger time of S250704ab, 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 86%
of the 90% credible region of the bayestar skymap from 05:48:11 to 06:01:46 UTC (T0+4643 to T0+5458 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.