Detecting short-term gravitational waves from post-merger hyper-massive neutron stars with a kilohertz detector

Abstract Gravitational waves emanating from binary neutron star inspirals, alongside electromagnetic transients resulting from the aftermath of the GW170817 merger, have been successfully detected. However, the intricate post-merger dynamics that bridge these two sets of observables remain enigmatic. This includes if, and when, the post-merger remnant star collapses to a black hole, and what are the necessary conditions to power a short gamma-ray burst, and other observed electromagnetic counterparts. Our focus is on the detection of GW emissions from hyper-massive neutron stars (NSs) formed through binary neutron star (BNS) mergers. Utilizing several kilohertz GW detectors, we simulate BNS mergers within the detection limits of LIGO-Virgo-KARGA O4. Our objective is to ascertain the fraction of simulated sources that may emit detectable post-merger GW signals. For kilohertz detectors equipped with a new cavity design, we estimate that approximately 1.1%-32% of sources would emit a detectable post-merger GW signal. This fraction is contingent on the mass converted into gravitational wave energy, ranging from 0.01 M ⊙ to 0.1 M ⊙ . Furthermore, by evaluating other well-regarded proposed kilohertz GW detectors, we anticipate that the fraction can increase to as much as 2.1%-61% under optimal performance conditions.