Quasi-universal Behavior of the Threshold Mass in Unequal-mass, Spinning Binary Neutron Star Mergers

The lifetime of the remnant produced by merger two neutron stars can provide a wealth information on equation state nuclear matter and processes leading to electromagnetic counterpart. Hence, it is essential determine when this shortest, corresponding has mass equal threshold mass, $M_{\rm th}$, prompt collapse black hole. We report results more than 360 simulations merging neutron-star binaries covering 40 different configurations differing in ratio spin primary. Using data, we have derived quasi-universal relation for th}$ expressed its dependence binary. new expression recovers Koeppel et al equal-mass, irrotational reveals that increase (decrease) $5\%~(10\%)$ spins aligned (anti-aligned) with orbital angular momentum provides evidence non-monotonic asymmetry system. Finally, extend unequal-masses spinning lower limits be set stellar radii once binary detected, illustrating how an unequal-mass, rapidly significantly constrain allowed values radii.