Distinguishability of a Naked Singularity from a Black Hole in Dynamics and Radiative Signatures

Abstract

Can a naked singularity (NkS) be distinguished from a black hole (BH)? We have investigated it with cutting-edge general relativistic magnetohydrodynamic simulations, followed by general relativistic radiation transfer calculation for magnetized accretion flow around NkS and BHs. Based on our simulations, the accreting matter close enough to the singularity repels due to effective potential. This prevents matter from reaching an NkS and forms a quasi-spherical symmetric density distribution around it, unlike the accretion flows around a BH. We observe 1 order of magnitude higher mass flux through the jet and much stronger wind from an NkS than a BH. We found that the jet launching mechanism in an NkS differs significantly from that in a BH. In the horizon-scale images, an NkS shows a photon arc instead of a photon ring that is shown around a BH. In summary, the flow dynamics and radiative properties around an NkS are distinctly different from a BH. These properties would be useful to either confirm or rule out such exotic compact objects through future observations.