Determination of the charge for strange stars

Abstract

Abstract Beginning from the proposal of a physically acceptable model to represent the interior of compact stars, in which their interior is formed by a strange matter distribution described by a charged fluid with anisotropic pressure, a MIT Bag equation of state for the radial pressure <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>P</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>r</mml:mi> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo> <mml:mfrac> <mml:mrow> <mml:mn>1</mml:mn> </mml:mrow> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> </mml:mfrac> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:mrow> <mml:msup> <mml:mrow> <mml:mi>c</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> <mml:mi>ρ</mml:mi> <mml:mo>−</mml:mo> <mml:mn>4</mml:mn> <mml:msub> <mml:mrow> <mml:mi>B</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>g</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> </mml:math> and metric functions given by a geometry that describes a regular, static and spherically symmetric space-time, we will determine the possible charge of some strange stars, or candidates, for which we know their radius and mass in an observational manner. As are: EXO 1785-248, SAX J1808.4-3658, SMC X-1, LMC X-4, Her X-1 and 4U 1538-52. The values of the Bag constant, B g , are found between 119.8 Mev/fm 3 and 176.41 Mev/fm 3 . Meanwhile the interval of the electric charge is found between 1.5453 × 10 18 C and 7.6271 × 10 19 C, the minimum corresponds to the star Her X-1 and the maximum to the star SMCX-1. Also, we show that for each fixed value of compactness u = GM / c 2 R , we obtain that, for greater values of the Bag constant the net charge diminishes and as the compactness increases the associated Bag constant increases as well.

Topics & Concepts