Constraining the Neutron Star Radius with Joint Gravitational-Wave and Short Gamma-Ray Burst Observations of Neutron Star-Black Hole Coalescing Binaries

Understand

Coalescing neutron star (NS)-black hole (BH) binaries are promising sources of gravitational-waves (GWs) to be detected within the next few years by current GW observatories.

• If the NS is tidally disrupted outside the BH innermost stable circular orbit, an accretion torus may form, and this could eventually power a short gamma-ray burst (SGRB).
• The observation of an SGRB in coincidence with gravitational radiation from an NS-BH coalescence would confirm the association between the two phenomena and also give us new insights on NS physics.
• We present here a new method to measure NS radii and thus constrain the NS equation of state using joint SGRB and GW observations of NS-BH mergers.