{
  "bibcode": "2019GCN.26229....1A",
  "body": "M. Arimoto (Kanazawa Univ.), M. Moss (GWU), S. Cutini (INFN Perugia),\nD. Kocevski (NASA/MSFC), N. Omodei (Stanford Univ.), M. Axelsson (KTH\nand Stockholm Univ.),\nE. Bissaldi (Politecnico and INFN Bari) and F. Longo (Univ. and INFN Trieste)\nreport on behalf of the Fermi-LAT Collaboration:\n\n\nWe have searched data collected by the Fermi Large Area Telescope (LAT)\non Nov 10, 2019, for possible high-energy (E > 100 MeV) gamma-ray emission\nin spatial/temporal coincidence with the LIGO/Virgo trigger S191110af\n(GCN 26222).\n\nWe define \"instantaneous coverage\" as the integral over the region\nof the LIGO probability map that is within the LAT field of view at a\ngiven time,\nand \"cumulative coverage\" as the integral of the instantaneous\ncoverage over time.\nFermi-LAT had an instantaneous coverage of ~18% of the LIGO probability region\nat the time of the trigger (T0 = 2019-11-10 23:06:44.183 UTC)\nand reached 100% cumulative coverage at approximately T0 + 5 ks.\n\nWe performed a search for a transient counterpart within the observed region\nof the 90% contour of the LIGO map in a fixed time window from T0 to T0 + 10 ks.\nNo significant sources were found.\n\nWe also performed a search which adapted the time interval of the analysis\nto the exposure of each region of the sky, and no additional excesses\nwere found.\n\nEnergy flux upper bounds between 100 MeV and 1 GeV\nfor the fixed time interval of this search vary\nbetween 2.3e-10 and 1.3e-7 [erg/cm^2/s].\n\nThe Fermi-LAT point of contact for this event\nis Michael Moss (michaelmoss@gwmail.gwu.edu).\n\nThe Fermi-LAT is a pair conversion telescope designed to cover\nthe energy band from 20 MeV to greater than 300 GeV.\nIt is the product of an international collaboration between\nNASA and DOE in the U.S. and many scientific institutions\nacross France, Italy, Japan and Sweden.",
  "circularId": 26229,
  "createdOn": 1573472677000,
  "email": "arimoto@hp.phys.titech.ac.jp",
  "subject": "LIGO/Virgo S191110af: No counterpart candidates in Fermi-LAT observations",
  "submitter": "Makoto Arimoto at Tokyo Inst of Tech  <arimoto@hp.phys.titech.ac.jp>",
  "eventId": "LIGO/Virgo S191110af"
}