LIGO/Virgo S190910d: Coverage and upper limits from MAXI/GSC observations

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.