We present the Fermi Large Area Telescope ( LAT ) observations of the binary neutron star merger event GW170817 and the associated short gamma-ray burst ( SGRB ) GRB 170817A detected by the Fermi Gamma-ray Burst Monitor .
The LAT was entering the South Atlantic Anomaly at the time of the LIGO/Virgo trigger ( t _ { GW } ) and therefore can not place constraints on the existence of high-energy ( E > 100 MeV ) emission associated with the moment of binary coalescence .
We focus instead on constraining high-energy emission on longer timescales .
No candidate electromagnetic counterpart was detected by the LAT on timescales of minutes , hours , or days after the LIGO/Virgo detection .
The resulting flux upper bound ( at 95 % C.L . )
from the LAT is 4.5 \times 10 ^ { -10 } erg cm ^ { -2 } s ^ { -1 } in the 0.1–1 GeV range covering a period from t _ { GW } + 1153 s to t _ { GW } + 2027 s. At the distance of GRB 170817A , this flux upper bound corresponds to a luminosity upper bound of 9.7 \times 10 ^ { 43 } erg s ^ { -1 } , which is 5 orders of magnitude less luminous than the only other LAT SGRB with known redshift , GRB 090510 .
We also discuss the prospects for LAT detection of electromagnetic counterparts to future gravitational wave events from Advanced LIGO/Virgo in the context of GW170817/GRB 170817A .