Browsing by Author "Sunzu, Jefta M."

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    Charged Anisotropic Composite Stellar Object with Strange, Polytropic and Gaseous Matter
    (Elsevier BV, 2023) Olengeile, Lilian; Sunzu, Jefta M.; Mkenyeleye, Jason Maombi
    In this study, we build a charged star model with three layers with distinct equations of state. The core, intermediate layer, and envelope layer obey linear, polytropic, and Chaplygin equations of state, respectively. The model satisfies the physical requirements for the matter variables, gravitational potentials, and stability conditions. We have generated within-acceptable range masses and radii for stars. We also recover the masses and radii for the stars PSRJ1903+0327, PSRJ1614-2230, SAXJ1808.4-3658, Vela X-1, and EXO1785-248 from earlier investigations which shows astrophysical significance of our model.
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    Double-layered anisotropic stellar model of embedding class I with gaseous envelope
    (Elsevier BV, 2023) Mathias, Amos Vincent; Mkenyeleye, Jason Maombi; Sunzu, Jefta M.
    The current paper presents a double-layered neutral anisotropic stellar model in general relativistic setting. The model is developed by using Einstein field equations and class I embedding condition. We consider the core with quark matter obeying linear equation of state and envelope layer with gaseous matter admitting Chaplygin gas equation of state. The interior and exterior metric coefficients match smoothly at the interface of core and envelope layers and at the stellar surface. The profiles for matter variables, stability and energy conditions show acceptable trend for physical stellar models. In this model, stellar masses and radii consistent with compact stars HerX-1, 4U1538-52, SAXJ1808.4-3658, CenX-3 and SMCX-1 are generated. We note that studies of multi-layered stars with gaseous envelope and embedding class I condition are missing in investigations conducted in the past.
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    Double-layered anisotropic stellar model of embedding class I with gaseous envelope
    (Elsevier, 2023) Mathias, Amos Vincent; Mkenyeleye, Jason Maombi; Sunzu, Jefta M.
    The current paper presents a double-layered neutral anisotropic stellar model in general relativistic setting. The model is developed by using Einstein field equations and class I embedding condition. We consider the core with quark matter obeying linear equation of state and envelope layer with gaseous matter admitting Chaplygin gas equation of state. The interior and exterior metric coefficients match smoothly at the interface of core and envelope layers and at the stellar surface. The profiles for matter variables, stability and energy conditions show acceptable trend for physical stellar models. In this model, stellar masses and radii consistent with compact stars HerX-1, 4U1538-52, SAXJ1808.4-3658, CenX-3 and SMCX-1 are generated. We note that studies of multi-layered stars with gaseous envelope and embedding class I condition are missing in investigations conducted in the past.