Effect of baryon number density (n) on the maximum mass and stability of strange stars

Abstract

A new class of relativistic solutions of Einstein field equations for an anisotropic strange star admitting the Vaidya-Tikekar type metric potential in the framework of MIT bag model equation of state of the strange matter, $p_r=\frac{1}{3}(\rho -4B)$, where B is termed as bag constant, is presented. In order to integrate the quark core hypothesis and provide an explanation for a physically feasible stellar model, we have examined the baryon number dependent B (n) via an extreme Wood-Saxon, like parameterisation. The energy per baryon $\left(E_B\right)$ has been calculated to restrict B (n) within the stable window, i.e., $E_B<930.4MeV$ $\left({}^{56}Fe\right)$. This study investigates the baryon number density (n) induced phase transition between hadrons and quarks inside a stellar configuration. Interestingly, the nature of the variation of $E_B$ vs. n, shows that for $n\ge 1.1f{m}^{-3}$ the energy per baryon approaches a constant value. We choose $n=0.6f{m}^{-3}$, $B=66.32MeV/f{m}^3$ within the stipulated restrictions and consider 4U 1608-52 as a strange star candidate. We find that all the characteristic properties are well satisfied within the stellar interior for the choice of parameters. The numerical solution of the TOV equations yields a maximum mass of strange quark stars of $2.01M_{\odot }$ and a corresponding radius of $10.96Km$. Proposed model meets the necessary energy conditions and also stability criteria, confirming its viability as a realistic stellar model within the parameter space used.