Living Reviews in Relativity https://doi.org/10.1007/s41114-020-00028-7(0123456789().,-volV)(0123456789().,-volV) REVIEW ARTICLE Neutron star mergers and how to study them Eric Burns1 Received: 5 January 2020 / Accepted: 12 October 2020 Ó The Author(s) 2020 Abstract Neutron star mergers are the canonical multimessenger events: they have been observed through photons for half a century, gravitational waves since 2017, and are likely to be sources of neutrinos and cosmic rays. Studies of these events enable unique insights into astrophysics, particles in the ultrarelativistic regime, the heavy element enrichment history through cosmic time, cosmology, dense matter, and fundamental physics. Uncovering this science requires vast observational resources, unparalleled coordination, and advancements in theory and simulation, which are constrained by our current understanding of nuclear, atomic, and astroparticle physics. This review begins with a summary of our current knowledge of these events, the expected observational signatures, and estimated detection rates for the next decade. I then present the key observations necessary to advance our under- standing of these sources, followed by the broad science this enables. I close with a discussion on the necessary future capabilities to fully utilize these enigmatic sources to understand our universe. Keywords Gravitational waves Á Neutron stars Á Black holes Á Nucleosynthesis Á Cosmology Á Equation of state Abbreviations BAO Baryon acoustic oscillation BAT Burst Alert Telescope BATSE Burst and Transient Source Experiment BBN Big Bang Nucleosynthesis BH Black Hole BBH Binary Black Hole BNS Binary Neutron Star CBC Compact Binary Coalescence & Eric Burns
[email protected] 1 Louisiana State University, Baton Rouge, LA 70803, USA 123 E.