Predicting the Electromagnetic Signatures of Compact Object Mergers

The ejection of radioactive material during, or immediately following, the merger of two neutron stars (or a neutron star and a black hole) can give rise to optical/infrared emission similar to, but dimmer and briefer than that of an ordinary supernova. These transients (called kilonovae) are promising electromagnetic counterparts to gravitational wave sources, and may be diagnostic of the sites of heavy element production. I will describe the physics of kilonovae, and present calculations that demonstrate how the color and brightness of such events carry information about the merger physics, such as the mechanism of mass ejection, the composition of outflows, the survival lifetime of a remnant hyper-massive neutron star, or the spin of a remnant black hole. These models inform observational strategies for finding kilonovae, and illustrate how we can use observations to better understand the sources of gravitational waves and the origin of the heavy elements in the Universe.

Speaker: Dan Kasen, UC Berkeley