Sawtooth-like oscillations of black hole accretion disks

Ryoji Matsumoto, Mami MacHida

Research output: Contribution to journalArticle

Abstract

We studied the origin of quasi-periodic oscillations (QPOs) of X-rays in black hole candidates by three-dimensional global resistive magnetohydrodynamic simulations of accretion disks. Initial state is a rotating disk threaded by weak toroidal magnetic fields. General relativistic effects are simulated by using the pseudo-Newtonian potential. When the temperature of the outer disk decreases, the accreting matter accumulates into an inner torus. We found that the inner torus is deformed into a crescent shape and that it shows sawtooth-like oscillations of magnetic energy with frequency 3-5Hz when the mass of the black hole is 10M. The magnetic energy inside the torus is amplified until magnetic reconnection suddenly releases the accumulated magnetic energy. A new cycle of the oscillation starts when magnetic energy is amplified again. We found that high frequency QPOs with frequency around 100Hz in stellar mass black holes are excited when sawtooth-like oscillation appears in the inner torus.

Original languageEnglish
Pages (from-to)37-42
Number of pages6
JournalProceedings of the International Astronomical Union
Volume2
Issue numberS238
DOIs
Publication statusPublished - Aug 1 2006
Externally publishedYes

Fingerprint

accretion disks
oscillation
accretion
oscillations
Rotating disks
Magnetohydrodynamics
energy
Magnetic fields
X rays
magnetohydrodynamic simulation
rotating disks
relativistic effects
magnetohydrodynamics
stellar mass
Temperature
magnetic field
cycles
magnetic fields
simulation
x rays

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)
  • Aerospace Engineering

Cite this

Sawtooth-like oscillations of black hole accretion disks. / Matsumoto, Ryoji; MacHida, Mami.

In: Proceedings of the International Astronomical Union, Vol. 2, No. S238, 01.08.2006, p. 37-42.

Research output: Contribution to journalArticle

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