{
  "bibcode": "2017GCN.20780....1S",
  "body": "S. Sugita, N. Kawai (Tokyo Tech), M. Serino (RIKEN), H. Negoro (Nihon U.),\nS. Ueno, H. Tomida, S. Nakahira, M. Ishikawa, Y. Sugawara (JAXA),\nY. E. Nakagawa (JAMSTEC),\nT. Mihara, M. Sugizaki, W. Iwakiri, M. Shidatsu, J. Sugimoto, T.\nTakagi, M. Matsuoka (RIKEN),\nN.Isobe, T. Yoshii, Y. Tachibana, Y. Ono, T. Fujiwara, S. Harita, Y.\nMuraki (Tokyo Tech),\nA. Yoshida, T. Sakamoto, Y. Kawakubo, Y. Kitaoka (AGU),\nH. Tsunemi, R. Shomura (Osaka U.),\nM. Nakajima, K. Tanaka, T. Masumitsu, T. Kawase (Nihon U.),\nY. Ueda, T. Kawamuro, T. Hori, A. Tanimoto, S. Oda (Kyoto U.),\nY. Tsuboi, Y. Nakamura, R. Sasaki (Chuo U.),\nM. Yamauchi, K. Furuya (Miyazaki U.),\nK. Yamaoka (Nagoya U.)\nreport on behalf of the MAXI team:\n\nWe examined the MAXI/GSC all-sky X-ray images (2-20 keV) obtained\nin the orbit and the day after the LVC trigger\nG274296 at 2017-02-17 06:05:55.050 UTC (GCN 20689) and\nG275404 at 2017-02-25 18:30:21.374 UTC (GCN 20738).\n\nMAXI/GSC did not observe (HV off) at the trigger time of G274296,\nand observed from T0+843 sec.\nMAXI/GSC scanned more than 87%\nof the whole sky in the 92-min orbit, which includes 77.4% of the\n90% regions in the skyprobcc_cWB skymap.\nOne day image covers 89.7% of the 90% regions\nin the skyprobcc_cWB skymap.\nNo significant new source was found in these images.\nThe upper limits for the X-ray flux are different depending\non the part of the sky.\nFor instance, typical 2-20 keV 1-sigma (3-sigma) upper limits obtained\nfrom the one-orbit and one-day images are\n40 (120) mCrab and 15 (35) mCrab, respectively,\nwhich was larger than the typical upper limits of GSC\nbecause anti-coincidence function of one of the GSC cameras was disabled.\n\nIn G275404 observation,\nMAXI/GSC did not observe at the trigger time\nand observed from T0+1246 sec.\nMAXI/GSC scanned more than 62%\nof the whole sky in the one orbit, which includes 55.0% of the\n90% regions in the bayestar skymap.\nOne day image covers 96.3% of the 90% regions\nin the bayestar skymap.\nNo significant new source was found in these images.\nFor instance, typical 2-20 keV 1-sigma (3-sigma) upper limits obtained\nfrom the one-orbit and one-day images are\n12 (36) mCrab and 3 (9) mCrab, respectively.\n\nMAXI/GSC also observed the position of the possible gamma-ray\ntransient (GCN 20754),\nbut it was difficult to estimate upper limits because the effect of stray photon\nfrom bright GRS 1915+105 near by the localized position of the transient\nwas large.",
  "circularId": 20780,
  "createdOn": 1488350250000,
  "email": "sugita@hp.phys.titech.ac.jp",
  "subject": "LIGO/Virgo G274296 and G275404 : MAXI/GSC observations",
  "submitter": "Satoshi Sugita at Tokyo Inst. of Tech.  <sugita@hp.phys.titech.ac.jp>",
  "eventId": "LIGO/Virgo G274296"
}