The evolution of binary neutron star post-merger remnants: a review

Understand

Two neutron stars merge somewhere in the Universe approximately every 10 seconds, creating violent explosions observable in gravitational waves and across the electromagnetic spectrum.

• The transformative coincident gravitational-wave and electromagnetic observations of the binary neutron star merger GW170817 gave invaluable insights into these cataclysmic collisions, probing bulk nuclear matter at supranuclear densities, the jet structure of gamma-ray bursts, the speed of gravity, and the cosmological evolution of the local Universe, among other things.
• Despite the wealth of information, it is still unclear when the remnant of GW170817 collapsed to form a black hole.
• Evidence from other short gamma-ray bursts indicates a large fraction of mergers may form long-lived neutron stars.