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

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

132
views

0
downloads

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

Suggestions

OpenMETU
Core

Frequency Resolved Spectroscopy of XB 1323-619 and EXO 0748-676 Balman, Şölen (2009-09-11) We present the frequency resolved energy spectra (FRS) of the low-mass X-ray binary dipper XB 1323-619 and EXO 0748-676 using archival XMM-Newton observations. The FRS of XB 1323-619 is well described by a single blackbody component with kT in a range 1.2-1.6 keV. We attribute this to an existing boundary layer, the likely source of the soft emission, supported by radiation pressure. We detect a different form of FRS for the frequency ranges 0.9-6 Hz and 8-30 Hz which is modeled best with a power law and a ...
X-ray flux and pulse frequency changes of three high mass X-ray binary pulsars: Vela X-1, GX 301-2 and OAO 1657-415 Inam, SC; Baykal, Altan (2000-01-01) Using archival BATSE (Burst and Transient Source Experiment) 20-50 keV band X-ray flux and pulse frequency time series, we look for correlations between torque, luminosity and specific angular momentum for three high mass X-ray binary pulsars Vela X-1, GX 301-2 and OAO 1657-415. Our results show that there is no correlation between pulse frequency derivative and flux which may be an indication of the absence of stable prograde accretion disk. From the strong correlation of specific angular momentum and torq...
X-ray analysis of high mass x-ray binary pulsars Şahiner, Şeyda; Baykal, Altan; İnam, Sıtkı Çağdaş; Department of Physics (2015) In this thesis, X-ray properties of three high mass X-ray binary (HMXB) pulsars are analysed, using the data of X-ray satellites such as RXTE, INTEGRAL and Swift. Selected sources belong to different subgroups of the HMXB family. The first system, 4U 1907+09 is a classical wind-fed supergiant system with persistent X-ray emission; although it shows irregular flares and dips. SWIFT J1729.9-3437 and SWIFT J0513.4-6547 are newly discovered transient systems. Although the counterpart of SWIFT J1729.9-3437 could...
Numerical analysis of long wavelength infrared HgCdTe photodiodes Kocer, H.; Arslan, Y.; Beşikci, Cengiz (2012-01-01) We present a detailed investigation of the performance limiting factors of long and very long wavelength infrared (LWIR and VLWIR) p on n Hg1-xCdxTe detectors through numerical simulations at 77 K incorporating all considerable generation-recombination (G-R) mechanisms including trap assisted tunneling (TAT), Shockley-Read-Hall (SRH), Auger and radiative processes. The results identify the relative strengths of the dark current generation mechanisms by numerically extracting the contribution of each G-R mec...
SOUND SOURCE LOCALISATION PERFORMANCE OF OPEN SPHERICAL ACOUSTIC INTENSITY PROBES UNDER REVERBERANT CONDITIONS Hacıhabiboğlu, Hüseyin (2014-04-25) Open-spherical acoustic intensity probes are microphone arrays based on the Kirchhoff-Helmholtz integral and are used in the measurement of active acoustic intensity. The acoustic intensity measurements obtained by these arrays can be used to localise sound sources. Previously, the performance of these arrays in acoustic free field conditions were obtained using numerical simulations and it was shown that they provide better performance than other types of probes. This paper discusses the implementation of ...

Citation Formats

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.