New class of anisotropic charged strange quark star in Durgapal \(IV\) metric and its maximum mass

Abstract

In this paper, we have explored the relativistic stellar model considering pressure anisotropy. An anisotropic solution of the Einstein Field Equations (henceforth EFE) has been presented for charged strange quark stars considering the interior space-time geometry described by the Durgapal \(IV^{th}\) metric. In the case of a strange quark star, if the equation of state \(p_{r}=\frac{1}{3}(\rho -4B_{g})\) as prescribed in the MIT bag model is applicable, then at the surface, one may consider that the surface energy density \(\rho _{s}=4B_{g}\). Imposing the constraint value of \(B_{g}\) within the range of 57.55 - \(95.11~MeV/fm^{3}\) required for stable quark matter with respect to a neutron when the external pressure is zero, we have determined the maximum mass and radius of the strange quark star and other relevant properties. It is noted that the maximum mass and radius for \(B_{g}=57.55~MeV/fm^{3}\) are \(M_{max}=2.92M_{\odot }\) and \(b_{max}=13.749~km\), respectively, whereas those for \(B_{g}=95.11~MeV/fm^{3}\), are \(M_{max}=2.27M_{\odot }\) and \(b_{max}=10.695~km\) for an isotropic uncharged star. In the presence of pressure anisotropy and charge, the value of maximum mass increases. We have predicted the radii of a few recently observed pulsars from our model and found that the radii agree with the predictions from observations. Furthermore, stability and energy conditions are also satisfied in the present model.