Relativistic compact stars in the Kuchowicz space-time

• Published in: Indian journal of physics 2021-06, Vol.95 (6), p.1271-1281
• Main Authors: Singh, K N, Rahaman, F, Pradhan, N, Pant, N
• Format: Article
• Language: English
• Subjects: Anisotropy; Astrophysics and Astroparticles; Configurations; Density; Mathematical models; Neutron stars; Original Paper; Parameters; Perturbation; Physics; Physics and Astronomy; Quark stars; Quarks; Relativistic effects
• ISSN: 0973-1458; 0974-9845
• DOI: 10.1007/s12648-020-01749-9

We present an anisotropic charged analogue of Kuchowicz (1971) solution of the general relativistic field equations in curvature coordinates by using simple form of electric intensity E and pressure anisotropy factor Δ that involve charge parameter K and anisotropy parameter α , respectively. Our solution is well behaved in all respects for all values of X ( X is related to the radius of the star) lying in the range 0 < X ≤ 0.6 , α lying in the range 0 ≤ α ≤ 1.3 , K lying in the range 0 < K ≤ 1.75 and Schwarzschild compactness parameter “ u ” lying in the range 0 < u ≤ 0.338 . Since our solution is well behaved for a wide range of the parameters, we can model many different types of ultra-cold compact stars like quark stars and neutron stars. We present some models of super-dense quark stars and neutron stars corresponding to X = 0.2 , α = 0.2 and K = 0.5 for which u max = 0.15 . By assuming surface density ρ b = 4.6888 × 10 14 g / c c , the mass and radius are 0.955 M ⊙ and 9.439 km , respectively. For ρ b = 2.7 × 10 14 g / c c , the mass and radius are 1.259 M ⊙ and 12.439 km , respectively, and for ρ b = 2 × 10 14 g / c c , the mass and radius are 1.463 M ⊙ and 14.453 km , respectively. It is also shown that inclusion of more electric charge and anisotropy enhances the static stable configuration under radial perturbations. The M - R graph suggests that the maximum mass of the configuration depends on the surface density, i.e., with the increase in surface density, the maximum mass and corresponding radius decrease. This may be because of existence of exotic matters at higher densities that soften the EoSs.