Premerger phenomena in neutron-star binary coalescences

Abstract

A variety of high-energy events can take place in the seconds leading up to a binary neutron-star merger. Mechanisms involving tidal resonances, electrodynamic interactions, or shocks in mass-loaded wakes have been proposed as instigators of these precursors. With a view of gravitational-wave and multimessenger astrophysics more broadly, premerger observations and theory are reviewed emphasising how gamma-ray precursors and dynamical tides can constrain the neutron-star equation of state, thermodynamic microphysics, and evolutionary pathways. Connections to post-merger phenomena, notably gamma-ray bursts, are discussed together with how magnetic fields, spin and misalignment, crustal elasticity, and stratification gradients impact observables.

Comments: 53 pages, 22 figures, 4 tables. To appear as an invited review for a special issue of Universe (Feature Papers 2024 - Compact Objects; Ed. N. Chamel). V6: Final changes to match published version, minor typos corrected