Towards incorporating a turbulent magnetic field in an accreting black hole model

Victor Kowalenko, Fulvio Melia

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

A model proposed by Melia & Ruffert to evaluate the spectrum and radiation flux for accretion on to a black hole makes use of the 'equipartition assumption' in which the magnetic, turbulent and gravitational energy densities are assumed to be in approximate equilibrium for distances below the accretion radius, where Bondi-Hoyle infall begins. As a consequence, the mechanism for the dissipation of the magnetic field and the resulting effect on the flow of the accreting gas have not been treated quantitatively. Here we examine alternative approaches for modelling the dissipation of magnetic fields and turbulent flow to see how these may be incorporated into the model. The results of our study should be immediately applicable to the ever-improving measurements of the spectrum and size of the massive black hole at our Galactic Centre, in particular producing a more accurate estimate of its mass. Combined with greatly refined kinematic studies of this region, our work may constrain the dark matter concentration in the nucleus of our Galaxy.

Original languageEnglish (US)
Pages (from-to)1053-1061
Number of pages9
JournalMonthly Notices of the Royal Astronomical Society
Volume310
Issue number4
StatePublished - Dec 21 1999

Fingerprint

dissipation
accretion
magnetic field
turbulent flow
magnetic fields
dark matter
kinematics
flux density
galaxies
nuclei
radii
radiation
estimates
gases
gas
modeling
energy
effect

Keywords

  • Accretion, accretion discs
  • Black hole physics
  • Galaxy: centre
  • Magnetic fields
  • Turbulence

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Towards incorporating a turbulent magnetic field in an accreting black hole model. / Kowalenko, Victor; Melia, Fulvio.

In: Monthly Notices of the Royal Astronomical Society, Vol. 310, No. 4, 21.12.1999, p. 1053-1061.

Research output: Contribution to journalArticle

@article{1866c6f934f3468383c4a269e0098b40,
title = "Towards incorporating a turbulent magnetic field in an accreting black hole model",
abstract = "A model proposed by Melia & Ruffert to evaluate the spectrum and radiation flux for accretion on to a black hole makes use of the 'equipartition assumption' in which the magnetic, turbulent and gravitational energy densities are assumed to be in approximate equilibrium for distances below the accretion radius, where Bondi-Hoyle infall begins. As a consequence, the mechanism for the dissipation of the magnetic field and the resulting effect on the flow of the accreting gas have not been treated quantitatively. Here we examine alternative approaches for modelling the dissipation of magnetic fields and turbulent flow to see how these may be incorporated into the model. The results of our study should be immediately applicable to the ever-improving measurements of the spectrum and size of the massive black hole at our Galactic Centre, in particular producing a more accurate estimate of its mass. Combined with greatly refined kinematic studies of this region, our work may constrain the dark matter concentration in the nucleus of our Galaxy.",
keywords = "Accretion, accretion discs, Black hole physics, Galaxy: centre, Magnetic fields, Turbulence",
author = "Victor Kowalenko and Fulvio Melia",
year = "1999",
month = "12",
day = "21",
language = "English (US)",
volume = "310",
pages = "1053--1061",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "4",

}

TY - JOUR

T1 - Towards incorporating a turbulent magnetic field in an accreting black hole model

AU - Kowalenko, Victor

AU - Melia, Fulvio

PY - 1999/12/21

Y1 - 1999/12/21

N2 - A model proposed by Melia & Ruffert to evaluate the spectrum and radiation flux for accretion on to a black hole makes use of the 'equipartition assumption' in which the magnetic, turbulent and gravitational energy densities are assumed to be in approximate equilibrium for distances below the accretion radius, where Bondi-Hoyle infall begins. As a consequence, the mechanism for the dissipation of the magnetic field and the resulting effect on the flow of the accreting gas have not been treated quantitatively. Here we examine alternative approaches for modelling the dissipation of magnetic fields and turbulent flow to see how these may be incorporated into the model. The results of our study should be immediately applicable to the ever-improving measurements of the spectrum and size of the massive black hole at our Galactic Centre, in particular producing a more accurate estimate of its mass. Combined with greatly refined kinematic studies of this region, our work may constrain the dark matter concentration in the nucleus of our Galaxy.

AB - A model proposed by Melia & Ruffert to evaluate the spectrum and radiation flux for accretion on to a black hole makes use of the 'equipartition assumption' in which the magnetic, turbulent and gravitational energy densities are assumed to be in approximate equilibrium for distances below the accretion radius, where Bondi-Hoyle infall begins. As a consequence, the mechanism for the dissipation of the magnetic field and the resulting effect on the flow of the accreting gas have not been treated quantitatively. Here we examine alternative approaches for modelling the dissipation of magnetic fields and turbulent flow to see how these may be incorporated into the model. The results of our study should be immediately applicable to the ever-improving measurements of the spectrum and size of the massive black hole at our Galactic Centre, in particular producing a more accurate estimate of its mass. Combined with greatly refined kinematic studies of this region, our work may constrain the dark matter concentration in the nucleus of our Galaxy.

KW - Accretion, accretion discs

KW - Black hole physics

KW - Galaxy: centre

KW - Magnetic fields

KW - Turbulence

UR - http://www.scopus.com/inward/record.url?scp=0041409687&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0041409687&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0041409687

VL - 310

SP - 1053

EP - 1061

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 4

ER -