TITLE:   GCN CIRCULAR
NUMBER:  25701
SUBJECT: LIGO/Virgo S190910d: Coverage and upper limits from MAXI/GSC observations
DATE:    19/09/10 07:03:55 GMT
FROM:    Motoko Serino at RIKEN/MAXI  <motoko@crab.riken.jp>

N. Kawai, M. Sugizaki (Tokyo Tech), H. Negoro (Nihon U.),
S. Sugita, M. Serino (AGU),
M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi (Nihon U.),
T. Mihara, T. Tamagawa, M. Matsuoka (RIKEN),
T. Sakamoto, H. Nishida, A. Yoshida (AGU),
Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, T. Sato (Chuo U.),
M. Shidatsu (Ehime U.), M. Oeda, K. Shiraishi (Tokyo Tech),
S. Nakahira, Y. Sugawara, S. Ueno, H. Tomida, M. Ishikawa, N. Isobe, R. Shimomukai, M. Tominaga (JAXA),
Y. Ueda, A. Tanimoto, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake (Kyoto U.),
H. Tsunemi, T. Yoneyama, K. Asakura, S. Ide (Osaka U.),
M. Yamauchi, S. Iwahori, Y. Kurihara, K. Kurogi, K. Miike (Miyazaki U.),
T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU)
report on behalf of the MAXI team:

We examined MAXI/GSC all-sky X-ray images (2-20 keV)
after the LVC trigger S190910d at 2019-09-10 01:26:19.242 UTC (GCN 25695).

At the trigger time of S190910d, 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 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 100%
of the 90% credible region of the bayestar skymap from 01:26:19 to 02:58:18 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.