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6 HZ QUASI-PERIODIC OSCILLATIONS FROM LOW-MASS X-RAY BINARIES - THE SOUND OF AN ACCRETION DISK
Date
1992-04-01
Author
ALPAR, MA
HASINGER, G
SHAHAM, J
YANCOPOULOS, S
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Quasiperiodic oscillations (QPOs) at frequencies of 5-8 Hz are a common feature of low-mass X-ray binaries (LMXBs) during their normal branch (NB) spectral states. We propose that this frequency band is essentially a band of rotation frequencies in a thick accretion disk. The high luminosities in the NB state give rise to the thick disk and slow down the dynamical timescales. Density and optical-thickness perturbations in a subsonic region of the disk have the frequency spectrum of sound in a rotating medium. X-rays scattered through the subsonic region are modulated by long wavelength optical-thickness oscillations whose frequencies, determined by the rotation rate and vorticity, are observed as the NB QPOs.
Subject Keywords
Accretion disks
,
X-Ray binaries
,
Quasi-periodic oscillations
,
Sound
URI
https://hdl.handle.net/11511/67411
Journal
ASTRONOMY & ASTROPHYSICS
Collections
Department of Physics, Article
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M. ALPAR, G. HASINGER, J. SHAHAM, and S. YANCOPOULOS, “6 HZ QUASI-PERIODIC OSCILLATIONS FROM LOW-MASS X-RAY BINARIES - THE SOUND OF AN ACCRETION DISK,”
ASTRONOMY & ASTROPHYSICS
, pp. 627–631, 1992, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/67411.