TITLE:   GCN CIRCULAR
NUMBER:  37520
SUBJECT: LIGO/Virgo/KAGRA S240915b: Coverage and upper limits from MAXI/GSC observations
DATE:    24/09/16 06:13:06 GMT
FROM:    Motoko Serino at Aoyama Gakuin U. <serino@phys.aoyama.ac.jp>

H. Nishikawa, S. Sugita, M. Serino, Y. Kawakubo, H. Hiramatsu, 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 S240915b at 2024-09-15 00:13:57.715 UTC (GCN 37512, 37513).

At the trigger time of S240915b, the high-voltage of MAXI/GSC was off,
and it was turned on at T0+707 sec (+11.8 min).
The first one-orbit (92 min) scan observation with GSC after the event covered 100%
of the 90% credible region of the Bilby skymap from 01:17:12 to 01:19:17 UTC (T0+3795 to T0+3920 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. 