TITLE: GCN CIRCULAR NUMBER: 21810 SUBJECT: LIGO/Virgo G298389: Fermi GBM Flux Upper Limits DATE: 17/09/04 15:32:46 GMT FROM: Rachel Hamburg at UAH LIGO/Virgo G298389: Fermi GBM Flux Upper Limits R. Hamburg (UAH) and C. Wilson-Hodge (NASA/MSFC) report on behalf of the GBM-LIGO Group: L. Blackburn (CfA), M. S. Briggs (UAH), J. Broida (Carleton College), E. Burns (NASA/GSFC), J. Camp (NASA/GSFC), T. Dal Canton (NASA/GSFC), N. Christensen (Carleton College), V. Connaughton (USRA), A. Goldstein (USRA), C. M. Hui (NASA/MSFC), P. Jenke (UAH), D. Kocevski (NASA/MSFC), N. Leroy (LAL), T. Littenberg (NASA/MSFC), J. McEnery (NASA/GSFC), R. Preece (UAH), J. Racusin (NASA/GSFC), P. Shawhan (UMD), K. Siellez (GA Tech), L. Singer (NASA/GSFC), J. Veitch (Birmingham), P. Veres (UAH) At the time of the LIGO/VIRGO candidate G298389, Fermi was passing through the South Atlantic Anomaly, and the GBM detectors were disabled. We set the following flux upper limits for the visible sky map within the 90% credible region. Using the Earth Occultation technique (Wilson-Hodge et al. 2012, ApJS, 201, 33) to estimate the amount of persistent emission during a 48-hour period centered on the LIGO trigger time, we place the following range of 3-sigma day-averaged flux upper limits based on observed sources over the entire 90% credible region of the LIGO sky map: Energy min max median ----------------------------------- 12-27 keV: 0.09 0.22 0.14 Crab 27-50 keV: 0.15 0.37 0.23 Crab 50-100 keV: 0.22 0.55 0.33 Crab 100-300 keV: 0.39 1.02 0.60 Crab 300-500 keV: 2.69 7.59 4.20 Crab These limits are based on the minimum requirement that each source in the Earth Occultation catalog was Earth-occulted at least 6 times in each of the 24 hour periods preceding and following the LIGO trigger and that the occultations were well separated from nearby bright sources.