Constraining the origin of high-energy emission from gravitational wave counterparts through MeV observations

Dr. Dan Kocevski

NASA Marshall Space Flight Center

The detection of GW170817 in gravitational waves (GWs) by LIGO/Virgo and GRB 170817A in gamma rays by the Fermi Gamma-ray Burst Monitor (GBM) and INTEGRAL SPI-ACS provided the first direct evidence for the long suspected connection between short gamma-ray bursts and merging neutron stars. The complementary information encoded in the electromagnetic signal showed that such observations can provide essential astrophysical context to GW detections. Despite the wealth of information that was gained by the multi-wavelength observations of GRB 170817A and the associated kilonova, many questions regarding the nature of the high-energy emission observed by GBM still remain and have become a source of vigorous debate within the community. I will discuss these open questions and present an overview of the theories that have been put forth to explain the high-energy observations. I will also propose future keV and MeV observations that would help better discriminate between these competing theories and give us further insight into the physical properties of these system.