TITLE: GCN CIRCULAR NUMBER: 38151 SUBJECT: LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations DATE: 24/11/10 03:10:03 GMT FROM: Motoko Serino at Aoyama Gakuin U. serino@phys.aoyama.ac.jp

Y. Kondo, S. Sugita, M. Serino, Y. Kawakubo, H. Hiramatsu, H. Nishikawa (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 S241109bn at 2024-11-09 11:59:24.899 UTC (GCN 38142, 38149).

At the trigger time of S241109bn, 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 Bilby 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 68% of the 90% credible region of the Bilby skymap from 11:59:24 to 13:31:23 UTC (T0+0 to T0+5519 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.

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