A Gaussian Model for Anisotropic Strange Quark Stars

For studying the anisotropic strange quark stars, we assume that the radial pressure inside an anisotropic star can be obtained simply by isotropic pressure plus an additional Gaussian term with three free parameters ($A$, $\mu$ and $\chi$). According to recent observations, a pulsar in a mass range of 1.97$\pm$0.04$M_{\odot}$ has been measured. Hence, we take this opportunity to set the free parameters of our model. We fix $\chi$ by applying boundary and stability conditions and then search the $A-\mu$ parameter space for a maximum mass range of $1.9M_{\odot} < M_{\max} < 2.1M_{\odot}$. Our results indicate that anisotropy increases the maximum mass $M_{\max}$ and also its corresponding radius $R$ for a typical strange quark star. Furthermore, our model shows magnetic field and electric charge increase the anisotropy factor ${\it \Delta}$. In fact, ${\it \Delta}$ has a maximum on the surface and this maximum goes up in the presence of magnetic field and electric charge. Finally, we show that anisotropy can be more effective than either magnetic field or electric charge in raising maximum mass of strange quark stars.