The Possibility of the Secondary Object in GW190814 as a Neutron Star

A compact object was observed with a mass of 2.50-2.67 M-circle dot 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 meanfield (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 2.55 M-circle dot with quite stiff equations of state generated by their strong repulsive contributions from vector potentials at high densities. Their maximum speeds of sound cs/c are smaller than 0.8 at the center of the neutron star, and the dimensionless tidal deformabilities at 1.4 M-circle dot are less than 800. Furthermore, the radii of 1.4 M-circle dot 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.