Neutron Star Mergers and Gravitational Waves: The Atomic Physics Connection

Neutron star mergers may reveal the cosmic origins of elements past the iron peak. During these highly energetic stellar mergers, neutron-rich material can assemble into heavy elements such as gold and uranium through rapid neutron capture (r-process) nucleosynthesis. The radioactive decay of these heavy elements powers a cascade of emission from gamma-rays to ultraviolet, optical, and infrared wavelengths, known as a kilonova. In this talk, I will present both the electromagnetic and gravitational-wave signatures of neutron star mergers, with a specific focus on rate estimates for current and upcoming gravitational-wave detectors, including the LIGO and Virgo interferometers. Additionally, I will describe efforts to constrain the cosmic origin of r-process elements through kilonova observations and motivate the essential role of atomic physics calculations in the process.