{
  "bibcode": "2017GCN.21534....1K",
  "body": "D. Kocevski (NASA/MSFC), N. Omodei (Stanford), S. Buson (NASA/GSFC), F. Longo (University and INFN, Trieste), J. Racusin (NASA/GSFC), and G. Vianello (Stanford) report on behalf of the Fermi-LAT team:   \n\nWe searched data collected by the Fermi Large Area Telescope (LAT) for possible high-energy (E > 100 MeV) gamma-ray emission in spatial/temporal coincidence with the LIGO/Virgo trigger G298048 .   \n\nThe Fermi gamma-ray space telescope was entering the South Atlantic Anomaly (SAA) at the time of the trigger (T0 = 2017-08-17 12:41:4.444 , 524666469.444 MET). During SAA passages the LAT does not collect data due to the high charged particle background in this region. We note that the SAA boundary employed by the LAT encompasses a larger area than the boundaries used by the the Gamma-ray Burst Monitor (GBM), resulting in different times at which the two instruments do not collect data. The LAT resumed data taking upon exiting the SAA at roughly T0 +1153 s,  At that time 100% of the BAYESTAR sky map using data from all three gravitational-wave observatories (H1, L1, and V1) (GCN 21513) was within the LAT field of view (FOV).   \n\nWe performed a search for a transient counterpart within the 90% contour of the LIGO/Virgo sky map in the time window from T0 + 1153s to T0 + 2027s, corresponding to the times when the region entered and exited the LAT FOV, and no significant new sources were found. We also performed a search which adapted the time interval of the analysis to the exposure of each region of the sky. No significant candidate counterpart was detected. \n\nThe Fermi-LAT point of contact for this event is Daniel Kocevski (daniel.kocevski@nasa.gov)    \n\nThe Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.\n\n\nDaniel Kocevski\nNASA Goddard Space Flight Center\nwww.kocevski.com\n510.316.3208",
  "circularId": 21534,
  "createdOn": 1503022193000,
  "email": "dankocevski@gmail.com",
  "subject": "LIGO/Virgo G298048 : Fermi-LAT search for a high-energy gamma-ray counterpart",
  "submitter": "Daniel Kocevski at NASA/MSFC  <dankocevski@gmail.com>",
  "eventId": "LIGO/Virgo G298048"
}