Spherical accretion in the Schwarzschild spacetime in the Newtonian analogous construct

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Ghosh, Shubhrangshu, Ghose, Souvik, Pal, Kalyanbrata, Bhadra, Arunabha, Das, Tapas K.
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866915184159752192
author Ghosh, Shubhrangshu
Ghose, Souvik
Pal, Kalyanbrata
Bhadra, Arunabha
Das, Tapas K.
author_facet Ghosh, Shubhrangshu
Ghose, Souvik
Pal, Kalyanbrata
Bhadra, Arunabha
Das, Tapas K.
contents The velocity-dependent Newtonian analogous potentials (NAPs) corresponding to general relativistic (GR) spacetimes accurately capture most of the relativistic features, including all classical tests of GR, effectively representing spacetime geometries in Newtonian terms. The NAP formulated by Tejeda \& Rosswog (TR13) for Schwarzschild spacetime has been applied to the standard thin accretion disk around a black hole (BH) as well as in the context of streamlines of noninteracting particles accreting onto a Schwarzschild BH, showing good agreement with the exact relativistic solutions. As a further application, here we explore the extent to which TR13 NAP could describe a transonic hydrodynamical spherical accretion flow in Schwarzschild spacetime within the framework of standard Newtonian hydrodynamics. Instead of obtaining a typical single "saddle-type" sonic transition, a "saddle-spiral pair" is produced, with the inner sonic point being an (unphysical) "spiral type" and the outer being a usual "saddle type." The Bondi accretion rate at outer sonic radii, however, remains consistent with that of the GR case. The primary reason for the deviation of our findings from the classical Bondi solution is likely due to the inconsistency between the Euler-type equation in the presence of velocity-dependent TR13 NAP within the standard Newtonian hydrodynamics framework, and the corresponding GR Euler equation, regardless of the fluid's energy. Our study suggests that a (modified) hydrodynamical formalism is needed to effectively implement such potentials in transonic accretion studies that align with the spirit of TR13-like NAP, while remaining consistent with the GR hydrodynamics. This could then essentially circumvent GR hydrodynamics or GR magnetohydrodynamics equations.
format Preprint
id arxiv_https___arxiv_org_abs_2503_04275
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Spherical accretion in the Schwarzschild spacetime in the Newtonian analogous construct
Ghosh, Shubhrangshu
Ghose, Souvik
Pal, Kalyanbrata
Bhadra, Arunabha
Das, Tapas K.
General Relativity and Quantum Cosmology
High Energy Astrophysical Phenomena
The velocity-dependent Newtonian analogous potentials (NAPs) corresponding to general relativistic (GR) spacetimes accurately capture most of the relativistic features, including all classical tests of GR, effectively representing spacetime geometries in Newtonian terms. The NAP formulated by Tejeda \& Rosswog (TR13) for Schwarzschild spacetime has been applied to the standard thin accretion disk around a black hole (BH) as well as in the context of streamlines of noninteracting particles accreting onto a Schwarzschild BH, showing good agreement with the exact relativistic solutions. As a further application, here we explore the extent to which TR13 NAP could describe a transonic hydrodynamical spherical accretion flow in Schwarzschild spacetime within the framework of standard Newtonian hydrodynamics. Instead of obtaining a typical single "saddle-type" sonic transition, a "saddle-spiral pair" is produced, with the inner sonic point being an (unphysical) "spiral type" and the outer being a usual "saddle type." The Bondi accretion rate at outer sonic radii, however, remains consistent with that of the GR case. The primary reason for the deviation of our findings from the classical Bondi solution is likely due to the inconsistency between the Euler-type equation in the presence of velocity-dependent TR13 NAP within the standard Newtonian hydrodynamics framework, and the corresponding GR Euler equation, regardless of the fluid's energy. Our study suggests that a (modified) hydrodynamical formalism is needed to effectively implement such potentials in transonic accretion studies that align with the spirit of TR13-like NAP, while remaining consistent with the GR hydrodynamics. This could then essentially circumvent GR hydrodynamics or GR magnetohydrodynamics equations.
title Spherical accretion in the Schwarzschild spacetime in the Newtonian analogous construct
topic General Relativity and Quantum Cosmology
High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2503.04275