Distinguishability of a naked singularity from a black hole in dynamics and radiative signatures

TL;DR

This study uses advanced simulations to show that naked singularities and black holes have distinct accretion flow dynamics and radiative signatures, which could help differentiate these objects observationally.

Contribution

The paper introduces detailed GRMHD and GRRT simulations revealing unique flow and radiative features of naked singularities compared to black holes.

Findings

Naked singularities repel matter, forming a spherical density distribution.

Naked singularities produce higher jet mass flux and stronger winds.

Photon arcs, not rings, appear in images of naked singularities.

Abstract

Can a naked singularity (NkS) be distinguished from a black hole (BH)? We have investigated it with cutting-edge general relativistic magneto-hydrodynamic (GRMHD) simulations, followed by general relativistic radiation transfer (GRRT) calculation for magnetized accretion flow around NkS and BH. Based on our simulations, the accreting matter close enough to the singularity repels due to effective potential. This prevents matter from reaching a NkS and forms a quasi-spherical symmetric density distribution around it, unlike the accretion flows around a BH. We observe an order of magnitude higher mass flux through the jet and much stronger wind from a NkS than a BH. We found that the jet launching mechanism in a NkS differs significantly from that in a BH. In the horizon-scale images, a 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.