Electrically charged strange quark stars with a non-linear equation-of-state

Grigoris Panotopoulos,Ángel Rincón

doi:10.1140/epjc/s10052-019-7042-7

Abstract

The properties of electrically charged strange quark stars are investigated. We assume a non-linear equation-of-state, and we obtain numerical solutions to the structure equations. The key features of the solutions obtained here are (i) they can support a 2 solar masses star, (ii) both the mass and the electric charge of the stars increase with the alpha parameter characterizing the electric density, (iii) the electric object is heavier and larger than its neutral counterpart.

Highlights

Compact objects [1,2,3] are the final fate of stars, and since they are characterized by ultra high matter densities the nonrelativistic Newtonian description is not adequate
Since real astronomical objects are expected to be electrically neutral, or at least without a significant amount of electric charge, in studies of compact relativistic astrophysical objects the authors usually focus on electrically neutral stars made of an isotropic fluid, and the interior solution is matched to the exterior Schwarzschild solution [20] on the surface of the object
Regarding strange quark stars with a non-vanishing electric charge, we are aware of the works of [29,30], where the well-studied linear equation-of-state for quark matter was used

Summary

Introduction

Compact objects [1,2,3] are the final fate of stars, and since they are characterized by ultra high matter densities the nonrelativistic Newtonian description is not adequate. Regarding strange quark stars with a non-vanishing electric charge, we are aware of the works of [29,30], where the well-studied linear equation-of-state for quark matter was used Despite the fact they are still theoretical objects, in the present work we propose to investigate the properties of electrically charged strange quarks stars adopting a non-linear equation-of-state instead, obtained in the framework of color superconductivity [31,32,33], assuming a non-vanishing energy gap and mass for the s quark. We adopt the mostly positive metric signature, (−, +, +, +), and we work in natural units where the speed of light in vacuum c as well as the reduced Planck constant hare set to unity, c = 1 = h In these units all dimensionful quantities are measured in GeV, 524 Page 2 of 6.

Structure equations

Equation-of-state

Numerical results

Conclusions