{
  "bibcode": "2019GCN.26468....1C",
  "body": "M. Crnogorcevic (Univ. of Maryland & NASA/GSFC), E. Moretti (IFAE,\nBarcelona), M. Axelsson (KTH & Stockholm Univ,), E. Bissaldi (Politecnico &\nINFN Bari), N. Omodei (Stanford University), M. Arimoto (Kanazawa Univ.)\nand F. Longo (University & INFN, Trieste) report on behalf of the Fermi-LAT\nCollaboration:\n\nWe have searched data collected by the Fermi Large Area Telescope (LAT) on\nDec 16, 2019, for possible high-energy (E > 100 MeV) gamma-ray emission in\nspatial/temporal coincidence with the LIGO/Virgo trigger S191216ap (GCN\n26454).\n\nWe define \"instantaneous coverage\" as the integral over the region of the\nLIGO probability map that is within the LAT field of view at a given time,\nand \"cumulative coverage\" as the integral of the instantaneous coverage\nover time. Fermi-LAT had an instantaneous coverage of ~80% of the LIGO\nprobability at the time of the trigger (T0 = 2019-12-16 21:33:38.474 UTC),\nand reached 100% cumulative coverage after ~4.5 ks.\n\nWe performed a search for a transient counterpart within the observed\nregion of the 90% contour of LIGO map in a fixed time window from T0 to T0\n+ 10 ks. No significant new sources are 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 were\nfound.\n\nEnergy flux upper bounds for the fixed time interval between 100 MeV and 1\nGeV for this search vary between 1.8e-10 and 3.1e-09 [erg/cm^2/s].\n\nThe Fermi-LAT point of contact for this event is Milena Crnogorcevic (\nmcrnogor@astro.umd.edu).\n\nThe Fermi-LAT is a pair conversion telescope designed to cover the energy\nband from 20 MeV to greater than 300 GeV. It is the product of an\ninternational collaboration between NASA and DOE in the U.S. and many\nscientific institutions across France, Italy, Japan and Sweden.\n\n\n\n-- \n\n\n\n\n*Institut de F��sica d'Altes Energies (IFAE) Universitat Aut��noma de\nBarcelona, Edifici Cn 08193 Bellaterra (Barcelona), Spain Tel:+34 931 70 27\n10Av��s - Aviso - Legal Notice - (LOPD) - http://legal.ifae.es\n<http://legal.ifae.es>*\n\n-- \nAv��s -\nAviso - Legal Notice - (LOPD) - http://legal.ifae.es \n<http://legal.ifae.es/>",
  "circularId": 26468,
  "createdOn": 1576581885000,
  "email": "moretti@ifae.es",
  "subject": "LIGO/Virgo G191216ap: No counterpart candidates in Fermi-LAT observations",
  "submitter": "Elena Moretti at IFAE,Barcelona  <moretti@ifae.es>",
  "eventId": "LIGO/Virgo G191216ap"
}