GRMHD modelling of accretion flow around Sagittarius A$^*$ constrained by EHT measurements

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Sen, Gargi, Maity, Debaprasad, Das, Santabrata
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915532741017600
author Sen, Gargi
Maity, Debaprasad
Das, Santabrata
author_facet Sen, Gargi
Maity, Debaprasad
Das, Santabrata
contents We study low angular momentum, advective accretion flows around a Kerr black hole within the framework of general relativistic magnetohydrodynamics (GRMHD) in the steady state. By solving the full set of GRMHD equations, we aim to provide a comprehensive understanding of the behavior of magnetized plasma in the strong gravity regime near a rotating black hole. The accretion solutions are obtained for a set of input parameters, namely energy (${\cal E}$), angular momentum (${\cal L}$), magnetic flux ($Φ$), and isorotation parameter ($I$). By systematically varying these parameters, we generate a family of global GRMHD accretion solutions that characterize the physical environment around the black hole. Using this approach, we investigate whether the inferred magnetic field strengths reported by the Event Horizon Telescope (EHT) for Sagittarius A$^*$ at various radii can be reproduced. We find that, for a broad range of parameter values, our model successfully recovers the EHT inferred magnetic field strengths with an accuracy of approximately $10\%$, offering a self-consistent framework for interpreting near-horizon accretion physics.
format Preprint
id arxiv_https___arxiv_org_abs_2510_03602
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle GRMHD modelling of accretion flow around Sagittarius A$^*$ constrained by EHT measurements
Sen, Gargi
Maity, Debaprasad
Das, Santabrata
High Energy Astrophysical Phenomena
We study low angular momentum, advective accretion flows around a Kerr black hole within the framework of general relativistic magnetohydrodynamics (GRMHD) in the steady state. By solving the full set of GRMHD equations, we aim to provide a comprehensive understanding of the behavior of magnetized plasma in the strong gravity regime near a rotating black hole. The accretion solutions are obtained for a set of input parameters, namely energy (${\cal E}$), angular momentum (${\cal L}$), magnetic flux ($Φ$), and isorotation parameter ($I$). By systematically varying these parameters, we generate a family of global GRMHD accretion solutions that characterize the physical environment around the black hole. Using this approach, we investigate whether the inferred magnetic field strengths reported by the Event Horizon Telescope (EHT) for Sagittarius A$^*$ at various radii can be reproduced. We find that, for a broad range of parameter values, our model successfully recovers the EHT inferred magnetic field strengths with an accuracy of approximately $10\%$, offering a self-consistent framework for interpreting near-horizon accretion physics.
title GRMHD modelling of accretion flow around Sagittarius A$^*$ constrained by EHT measurements
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2510.03602