Comparison among three types of relativistic charged anisotropic fluid spheres for self-bound stars

The number of exact solutions for spherically symmetric anisotropic fluid spheres is derived. And the relativistic model of an electrically charged compact star whose energy density associated with the electric fields is on the same order of magnitude as the energy density of fluid matter itself, such as electrically charged bare strange stars is also investigated. Among the three models, Heintzmann and Durgapal IV, and V permit a simple method that provide bounds on the maximum possible mass of compact electrically charged self-bound stars, and numerically exhibit that the maximum compactness and mass increase in the presence of an electric field and anisotropic pressure. Based on analytic models developed in this work, it has been compared to investigate which one is better than the others; the values of some pertinent physical quantities have been considered by assuming the estimated masses and radii of some well-known potential strange star candidates like Vela X-1, Cen X-3, PSR J1903+327 and EXO 1785-248. This analysis depends on several mathematical assumptions.