W190814’s Secondary Component with Mass (2.50 − 2.67) Msun as a Super-fast Pulsar

Zhang, Naibo

Using Stergioulas’s RNS code for investigating fast pulsars with Equation of States (EOSs) on the causality surface (where the speed of sound equals to that of light) of the high-density EOS parameter space satisfying all known constraints from both nuclear physics and astrophysics, we show that the GW190814’s secondary component of mass (2.50 − 2.67) M_sun can be a super-fast pulsar spinning faster than 971 Hz about 42% below its Kepler frequency. There is a large and physically allowed EOS parameter space below the causality surface where pulsars heavier than 2.50 M_sun are supported if they can rotate even faster with critical frequencies depending strongly on the high-density behavior of nuclear symmetry energy.