TITLE: GCN CIRCULAR NUMBER: 24926 SUBJECT: LIGO/Virgo S190630ag: Coverage and upper limits from MAXI/GSC observations DATE: 19/06/30 23:35:26 GMT FROM: Satoshi Sugita at Aoyama Gakuin U. 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.), S. Nakahira, 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. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara, 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 S190630ag at 2019-06-30 18:52:05.179 UTC (GCN 24922). At the trigger time of S190630ag, the high-voltage of MAXI/GSC was off, and it was turned on at T0+176 sec (+2.9 min). The first one-orbit (92 min) scan observation with GSC after the event covered 60% of the 90% credible region of the bayestar skymap from 18:58:20 to 20:05:46 UTC (T0+375 to T0+4421 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.