Ionization, magnetorotational, and gravitational instabilities in thin accretion disks around supermassive black holes

Kristen Menou, Eliot Quataert

Research output: Contribution to journalArticle

51 Scopus citations

Abstract

We consider the combined role of the thermal ionization, magnetorotational, and gravitational instabilities in thin accretion disks around supermassive black holes. We find that in the portions of the disk unstable to the ionization instability, the gas remains well coupled to the magnetic field even on the cold, neutral branch of the thermal limit cycle. This suggests that the ionization instability is not a significant source of large-amplitude time-dependent accretion in active galactic nuclei (AGNs). We also argue that, for Ṁ ≳ 10-2 M yr-1, the gravitationally unstable and magnetorotationally unstable regions of the accretion disk overlap; for lower accretion rates they may not. Some low-luminosity AGN, e.g., NGC 4258, may thus be in a transient phase in which mass is building up in a nonaccreting gravitationally and magnetorotationally stable "dead zone." We comment on possible implications of these findings.

Original languageEnglish (US)
Pages (from-to)204-208
Number of pages5
JournalAstrophysical Journal
Volume552
Issue number1 PART 1
DOIs
StatePublished - May 1 2001
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Keywords

  • Accretion, accretion disks
  • Black hole physics
  • Galaxies: nuclei
  • MHD
  • Quasars: general
  • Turbulence

Fingerprint Dive into the research topics of 'Ionization, magnetorotational, and gravitational instabilities in thin accretion disks around supermassive black holes'. Together they form a unique fingerprint.

Cite this