Relativistic model of anisotropic charged fluid sphere in general relativity

Abstract

In this present paper, we present a class of static, spherically symmetric charged anisotropic fluid models of super dense stars in isotropic coordinates by considering a particular type of metric potential, a specific choice of electric field intensity $E$ and pressure anisotropy factor $\Delta$ which involve parameters $K$ (charge) and $\alpha$ (anisotropy) respectively. The solutions so obtained are utilized to construct the models for super-dense stars like neutron stars and strange quark stars. Our solutions are well behaved within the following ranges of different constant parameters. In the absence of pressure anisotropy and charge present model reduces to the isotropic model Pant et al. (Astrophys. Space Sci. 330:353–359, 2010). Our solution is well behaved in all respects for all values of $X$ lying in the range $0< X \leq 0.18$, $\alpha$ lying in the range $0 \leq \alpha \leq6.6$, $K$ lying in the range $0< K \leq 6.6$ and Schwarzschild compactness parameter “$u$” lying in the range $0< u \leq 0.38$. Since our solution is well behaved for a wide ranges of the parameters, we can model many different types of ultra-cold compact stars like quark stars and neutron stars. We have shown that corresponding to $X=0.088$, $\alpha=0.6$ and $K=4.3$ for which $u=0.2054$ and by assuming surface density $\rho_{b} = 4.6888 \times 10^{14}~\mbox{g/cm}^{3}$ the mass and radius are found to be $1.51~M_{\varTheta}$ and 10.90 km respectively. Assuming surface density $\rho_{b} = 2 \times 10^{14}~\mbox{g/cm}^{3}$ the mass and radius for a neutron star candidate are found to be $2.313~M_{\varTheta}$ and 16.690 km respectively. Hence we obtain masses and radii that fall in the range of what is generally expected for quark stars and neutron stars.