2020ApJ...904...39H

A compact object was observed with a mass of 2.50–2.67M_☉ by LIGO Scientific and Virgo collaborations (LVC) in GW190814, which provides a great challenge to investigations of supranuclear matter. To study this object, the properties of the neutron star are systematically calculated within the latest density-dependent relativistic mean-field (DDRMF) parameterizations, which are determined by the ground-state properties of spherical nuclei. The maximum masses of the neutron star calculated by DD-MEX and DD-LZ1 sets can be around 2.55M_☉ with quite stiff equations of state generated by their strong repulsive contributions from vector potentials at high densities. Their maximum speeds of sound c_s/c are smaller than sqrt(0)at the center of the neutron star, and the dimensionless tidal deformabilities at 1.4M_☉ are less than 800. Furthermore, the radii of 1.4M_☉ also satisfy the constraint from the observation of simultaneous mass-radius measurements (Neutron star Interior Composition Explorer). Therefore, we conclude that one cannot exclude the possibility of the secondary object in GW190814 as a neutron star composed of hadron matter from DDRMF models.