Explosions in the MeV Sky: Gamma-ray Bursts and Gravitational Wave Counterparts

Dr. Judith Racusin

NASA Goddard Space Flight Center

Gamma-ray bursts (GRBs) are the brightest transients in the MeV sky, and their association with gravitational wave counterparts is a topic at the forefront of multi-messenger astrophysics. GRBs have been studied for decades with wide-field-of-view background-dominated monitoring instruments, but with a sensitive MeV instrument like AMEGO, there is great potential for understanding the fainter populations of nearby short duration GRBs within the gravitational wave detector horizons, including those that may be slightly off-axis like GRB 170817A associated with GW170817. Initial estimates suggest that AMEGO will be the most prolific detector of GRBs to have ever flown, and will also be sensitive to a significant number of long duration GRBs at high redshifts (z > 5). Sensitive MeV observations of GRB spectral and temporal evolution as well as potentially polarization of bright events, will provide insight into GRB prompt emission mechanisms, as well as probe synchrotron shocks physics by measuring MeV GRB afterglows of bright bursts.