Radiative-hydrodynamical simulations of accretion disk coronae

Fulvio Melia, Gregory J. Zylstra, Bruce Fryxell

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

We have developed an algorithm that will carry out detailed, two-dimensional, fully self-consistent radiative-hydrodynamical simulations of accretion disk coronae in X-ray-luminous compact sources. The calculation reported here, for an accreting neutron star radiating at 0.5 times the Eddington luminosity, reveals several striking features. (1) The corona is comprised of two main regions - an inner (r ≲1 × 108 cm) highly dynamic portion whose vertical structure varies cyclically on a dynamical time scale (∼0.2 s), and an outer, more stable zone in which the evaporated plasma rises to form a "sheath" that gradually merges into a wind at large radii. (2) The coronal structure shows a density inversion (due to the ram pressure support of the ionized flow) that contrasts sharply with the Gaussian profiles of earlier hydrostatic models. (3) Interestingly, flow velocities as high as a few × 109 cm s-1 are not uncommon in portions of the corona. We discuss the relevance of this point to the large measured width of the emission features seen in low-mass X-ray binaries and the Galactic black hole candidates.

Original languageEnglish (US)
JournalAstrophysical Journal
Volume377
Issue number2 PART 2
StatePublished - Aug 20 1991

Fingerprint

accretion disks
coronas
corona
accretion
simulation
ram
hydrostatics
sheaths
flow velocity
neutron stars
x rays
luminosity
inversions
timescale
plasma
radii
profiles
calculation
inversion

Keywords

  • Black holes
  • Radiative transfer
  • Stars: accretion
  • Stars: binaries
  • Stars: coronae
  • Stars: neutron

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Radiative-hydrodynamical simulations of accretion disk coronae. / Melia, Fulvio; Zylstra, Gregory J.; Fryxell, Bruce.

In: Astrophysical Journal, Vol. 377, No. 2 PART 2, 20.08.1991.

Research output: Contribution to journalArticle

Melia, F, Zylstra, GJ & Fryxell, B 1991, 'Radiative-hydrodynamical simulations of accretion disk coronae', Astrophysical Journal, vol. 377, no. 2 PART 2.
Melia, Fulvio ; Zylstra, Gregory J. ; Fryxell, Bruce. / Radiative-hydrodynamical simulations of accretion disk coronae. In: Astrophysical Journal. 1991 ; Vol. 377, No. 2 PART 2.
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