Difference: GCNCIRCULAR20767 ( vs. 1)

E. Burns (UAH) reports on behalf of the GBM-LIGO Group: Lindy Blackburn (CfA), Michael S. Briggs (UAH), Jacob Broida (Carleton College), Jordan Camp (NASA/GSFC), Tito Dal Canton (NASA/GSFC), Nelson Christensen (Carleton College), Valerie Connaughton (USRA), Adam Goldstein (USRA), Rachel Hamburg (UAH), C. Michelle Hui (NASA/MSFC), Pete Jenke (UAH), Dan Kocevski (NASA/MSFC), Nicolas Leroy (LAL), Tyson Littenberg (NASA/MSFC), Julie McEnery (NASA/GSFC), Rob Preece (UAH), Judith Racusin (NASA/GSFC), Peter Shawhan (UMD), Karelle Siellez (GA Tech), Leo Singer (NASA/GSFC), John Veitch (Birmingham), Peter Veres (UAH), Colleen Wilson-Hodge (NASA/MSFC)

GBM was observing 69% of the LIGO probability map for G275697 at the event time, with about half of the northern high probability region and all of the southern arc observed. There is no GBM on-board trigger around the event time. The untargeted ground-based search of GBM data for short-duration GRBs (Briggs et al., in prep) found no candidates close in time to G275697, though it has only run through 19:00. The targeted search of the GBM data ([1], [2]) also did not find a significant gamma-ray signal. This search processes time scales of 0.256 to 8.192 s within 30 s of the LIGO event. No interesting gamma-ray candidate was found within this time window.

Any prompt gamma-ray burst emission, above the GBM detection threshold, must have been occulted by the Earth for Fermi. The Earth-occulted region is a circle with radius of 68 degrees, centered on RA, Dec = 326.9, -22.8.

Further analysis and upper limits will be reported later.

[1] L. Blackburn et al. 2015, ApjS 217, 8 [2] A. Goldstein et al. arXiv:1612.02395

-- ThomasKupfer - 27 Feb 2017