Stellar Structure and Stability of Charged Interacting Quark Stars and Their Scaling Behaviour

TL;DR

This paper investigates the structure and stability of charged quark stars with interacting quark matter, analyzing how charge and model parameters influence their mass, radius, and stability, including novel configurations with zero central pressure.

Contribution

It introduces a general parametrization of the quark matter equation of state and explores the effects of charge and model parameters on stellar structure and stability, revealing new stellar configurations.

Findings

Increasing charge increases star mass and radius.

Charge model and parameter $ar{ extlambda}$ influence stability and structure.

Discovery of stellar configurations with zero central pressure and finite mass.

Abstract

We explore the stellar structure and radial stability of charged quark stars composed of interacting quark matter (IQM) in three classes of commonly used charge models. We adopt a general parametrization of IQM equation of state that includes the corrections from perturbative QCD, color superconductivity, and the strange quark mass into one parameter $\lambda$, or one dimensionless parameter $\bar{\lambda}=\lambda^2/(4B_{\rm eff})$ after being rescaled with the effective bag constant $B_{\rm eff}$. We find that increasing charge tends to increase the mass and radius profiles, and enlarges the separation size in mass between the maximum mass point and the point where zero eigenfrequencies $\omega^2_0=0$ of the fundamental radial oscillation mode occur. The sign of the separation in central density depends on the charge model; this separation also has a dependence on $\lambda$ such that increasing $\lambda$ (which can occur for either large color superconductivity or small strange quark mass) tends to decrease this separation size for the first and third classes of charge models monotonically. Moreover, for the second and third classes of charge models, we manage to numerically and analytically identify a new kind of stellar structure with a zero central pressure but a finite radius and mass. All the calculations and analysis are performed in a general dimensionless rescaling approach so that the results are independent of explicit values of dimensional parameters.