Comparing accretion disk profiles of Bogush–Galt’sov naked singularity and Kerr black hole

Abstract It is well known that the Einstein-scalar system of general relativity can in principle yield non-unique exact spinning naked singularities, which lead to unique Kerr black hole when the scalar field is switched off. It is a challenging task to observationally distinguish these two types of...

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Main Authors: R. Kh. Karimov, R. N. Izmailov, A. A. Potapov, K. K. Nandi
Format: Article
Language:English
Published: SpringerOpen 2022-03-01
Series:European Physical Journal C: Particles and Fields
Online Access:https://doi.org/10.1140/epjc/s10052-022-10205-3
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author R. Kh. Karimov
R. N. Izmailov
A. A. Potapov
K. K. Nandi
author_facet R. Kh. Karimov
R. N. Izmailov
A. A. Potapov
K. K. Nandi
author_sort R. Kh. Karimov
collection DOAJ
description Abstract It is well known that the Einstein-scalar system of general relativity can in principle yield non-unique exact spinning naked singularities, which lead to unique Kerr black hole when the scalar field is switched off. It is a challenging task to observationally distinguish these two types of objects. Since accretion process could be a viable diagnostic for this distinction, the purpose of the present work is to explore whether there could be features in the accretion profiles distinguishing the singularity from a Kerr black hole. Here we study the Novikov–Thorne thin accretion to a new spinning naked singularity with a scalar charge $$\sigma $$ σ recently reported by Bogush and Gal’tsov (BG). Our study reveals that: (1) the conversion efficiency $$\epsilon $$ ϵ of the BG naked singularity is independent of $$\sigma $$ σ and (2) the maxima of emissivity profiles for the BG singularity tend to shift towards the inner disk ISCO boundary $$r=r_{{ms }}$$ r = r ms and peak at a value significantly larger than those of a Kerr black hole with the increase of a, $$\sigma $$ σ and relative shrinking of $$\sqrt{-g}$$ - g . All these effects are quantitatively tabulated, which reveal, for instance, that the flux from the naked singularity could be as high as $$10^{5}$$ 10 5 times larger than that of a Kerr black hole. Since these distinguishing features are known to be shared also by other models of naked singularity, it is tempting to speculate that such behavior could be hallmark of naked singularities.
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spelling doaj.art-f424f0f9cc504299bfd6372b1e962bdf2022-12-22T02:39:32ZengSpringerOpenEuropean Physical Journal C: Particles and Fields1434-60441434-60522022-03-0182311110.1140/epjc/s10052-022-10205-3Comparing accretion disk profiles of Bogush–Galt’sov naked singularity and Kerr black holeR. Kh. Karimov0R. N. Izmailov1A. A. Potapov2K. K. Nandi3Zel’dovich International Center for Astrophysics, M. Akmullah Bashkir State Pedagogical UniversityZel’dovich International Center for Astrophysics, M. Akmullah Bashkir State Pedagogical UniversityDepartment of Physics and Astronomy, Bashkir State UniversityZel’dovich International Center for Astrophysics, M. Akmullah Bashkir State Pedagogical UniversityAbstract It is well known that the Einstein-scalar system of general relativity can in principle yield non-unique exact spinning naked singularities, which lead to unique Kerr black hole when the scalar field is switched off. It is a challenging task to observationally distinguish these two types of objects. Since accretion process could be a viable diagnostic for this distinction, the purpose of the present work is to explore whether there could be features in the accretion profiles distinguishing the singularity from a Kerr black hole. Here we study the Novikov–Thorne thin accretion to a new spinning naked singularity with a scalar charge $$\sigma $$ σ recently reported by Bogush and Gal’tsov (BG). Our study reveals that: (1) the conversion efficiency $$\epsilon $$ ϵ of the BG naked singularity is independent of $$\sigma $$ σ and (2) the maxima of emissivity profiles for the BG singularity tend to shift towards the inner disk ISCO boundary $$r=r_{{ms }}$$ r = r ms and peak at a value significantly larger than those of a Kerr black hole with the increase of a, $$\sigma $$ σ and relative shrinking of $$\sqrt{-g}$$ - g . All these effects are quantitatively tabulated, which reveal, for instance, that the flux from the naked singularity could be as high as $$10^{5}$$ 10 5 times larger than that of a Kerr black hole. Since these distinguishing features are known to be shared also by other models of naked singularity, it is tempting to speculate that such behavior could be hallmark of naked singularities.https://doi.org/10.1140/epjc/s10052-022-10205-3
spellingShingle R. Kh. Karimov
R. N. Izmailov
A. A. Potapov
K. K. Nandi
Comparing accretion disk profiles of Bogush–Galt’sov naked singularity and Kerr black hole
European Physical Journal C: Particles and Fields
title Comparing accretion disk profiles of Bogush–Galt’sov naked singularity and Kerr black hole
title_full Comparing accretion disk profiles of Bogush–Galt’sov naked singularity and Kerr black hole
title_fullStr Comparing accretion disk profiles of Bogush–Galt’sov naked singularity and Kerr black hole
title_full_unstemmed Comparing accretion disk profiles of Bogush–Galt’sov naked singularity and Kerr black hole
title_short Comparing accretion disk profiles of Bogush–Galt’sov naked singularity and Kerr black hole
title_sort comparing accretion disk profiles of bogush galt sov naked singularity and kerr black hole
url https://doi.org/10.1140/epjc/s10052-022-10205-3
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