Generalized JMN Naked Singularity Models

We construct a generalized class of Joshi-Malafarina-Narayan (JMN) naked singularity spacetimes that arise as equilibrium end states of gravitational collapse with non-vanishing tangential pressure. The generalization introduces density inhomogeneity through a radially dependent mass function F(r)=(M 0+M n r n)r cubed, leading to a two-parameter family of solutions matched smoothly to an exterior Schwarzschild spacetime. The observational properties of the spacetime are then examined through shadow formation and thin accretion disk emission. We find that when the photon sphere lies in the exterior Schwarzschild region, the shadow is identical to that of a Schwarzschild black hole. Accretion disk spectra show enhanced high-frequency emission compared to Schwarzschild, while deviations from the original JMN model remain small due to strong constraints on the inhomogeneity parameter. These results indicate that the generalized model effectively serves as a small perturbation of the JMN spacetime, demonstrating the robustness of JMN-type naked-singularity geometries.