Spherical configuration of a super-dense hot compact object with particular EoS

TL;DR

This paper proposes a specific equation of state for super-dense compact objects, demonstrating stable configurations at sub-critical temperatures and deriving their mass-radius relations consistent with experimental and theoretical constraints.

Contribution

It introduces a novel EoS allowing liquid-phase super-dense matter and derives mass-radius relations for small stellar remnants using TOV equations.

Findings

Stable configurations exist below critical temperature.

Derived mass-radius relations match experimental constraints.

Objects have masses smaller than the Sun.

Abstract

The equation of state (EoS) $P = P (\rho, ...)$ -- pressure as a function of density and other thermodynamical quantities -- is what generates particularities of mass--radius distribution $M (R)$ for super--dense compact stellar bodies, the remnants of cosmic cataclysms. In view of recent nuclear experiments, we propose one particular EoS, which admits the critical state characterized by density $\rho_c$ and temperature $T_c$, and which under certain conditions permits a radial distribution of the super--dense matter in "liquid" phase. We establish such conditions and demonstrate that a stable configuration is indeed possible (only) for temperatures smaller than the critical one. Using Tolman--Oppenheimer--Volkoff equations for hydrostatic equilibrium, we derive the mass--radius relation for the super--dense compact objects with masses smaller than the Sun, $M \ll M_{\odot}$. The obtained results are within the constraints established by both heavy--ion collision experiments and theoretical studies of neutron--rich matter.