The spectra of accretion disks and their application to low-mass X-ray binaries

1987 ◽  
Vol 322 ◽  
pp. 329 ◽  
Author(s):  
Ronald E. Taam ◽  
P. Meszaros
Keyword(s):  
Accretion Disks ◽  
X Ray ◽  
Low Mass ◽  
X Ray Binaries

scholarly journals Modeling of Oxygen-Neon Dominated Accretion Disks in Ultracompact X-Ray Binaries: 4U 1626-67

2004 ◽  
Vol 194 ◽  
pp. 146-147 ◽  
Author(s):  
K. Werner ◽  
T. Nagel ◽  
S. Dreizler ◽  
T. Rauch
Keyword(s):  
Accretion Disks ◽  
Important Process ◽  
Gravitational Settling ◽  
X Ray ◽  
The Core ◽  
Synthetic Spectra ◽  
First Results ◽  
Low Mass ◽  
X Ray Binaries

AbstractWe report on first results of computing synthetic spectra from H/He-poor accretion disks in ultracompact LMXBs. We aim at the determination of the chemical composition of the very low-mass donor star, which is the core of a former C/O white dwarf. The abundance analysis allows to draw conclusions on gravitational settling in WDs which is an important process affecting cooling times and pulsational g-mode periods.

scholarly journals Magnetically Driven Warping and Precession of Accretion Disks: Implications for Exotic Stellar Variabilities

2002 ◽  
Vol 187 ◽  
pp. 215-220
Author(s):  
Dong Lai
Keyword(s):  
Accretion Disks ◽  
Low Frequency ◽  
Disk Accretion ◽  
X Ray ◽  
T Tauri ◽  
Magnetic Stars ◽  
Low Mass ◽  
Inner Region ◽  
X Ray Binaries

AbstractThe inner region of the accretion disk around a magnetized star is subjected to magnetic torques that induce warping and precession of the disk. These torques arise from interactions between the stellar field and the induced electric currents in the disk. These novel magnetic effects give rise to some “exotic” stellar variabilities, and may play an important role in explaining a number of puzzling behaviors related to disk accretion onto magnetic stars, such as mHz QPOs in X-ray pulsars, long-term periodicities of X-ray binaries (including precession of jets), low-Frequency (10-50 Hz) QPO’s in low-mass X-ray binaries, and photometric variabilities of T Tauri stars.

scholarly journals Non-Linear Resonances in Accretion Disks and QPOs

2004 ◽  
Vol 194 ◽  
pp. 128-129
Author(s):  
Włodek Kluźniak
Keyword(s):  
Black Holes ◽  
Neutron Stars ◽  
Accretion Disk ◽  
Accretion Disks ◽  
High Frequency ◽  
Light Curves ◽  
X Ray ◽  
Non Linear ◽  
Low Mass ◽  
X Ray Binaries

AbstractNon-linear oscillations in the accretion disk are favored as an explanation of high-frequency QPOs observed in the light curves of low-mass X-ray binaries containing neutron stars, black holes, or white dwarfs.

scholarly journals A possible origin of kilohertz quasi-periodic oscillations in low-mass X-ray binaries

2020 ◽  
Vol 72 (3) ◽  
Author(s):  
Shoji Kato ◽  
Mami Machida
Keyword(s):  
Accretion Disks ◽  
Radial Direction ◽  
Rotational Instability ◽  
Periodic Oscillations ◽  
X Ray ◽  
Resonant Instability ◽  
Low Mass ◽  
Magnetohydrodynamic Simulations ◽  
X Ray Binaries ◽  
Possible Cause

Abstract A possible origin of kilohertz quasi-periodic oscillations (QPOs) in low-mass X-ray binaries is proposed. Recent numerical magnetohydrodynamic simulations of accretion disks with turbulent magnetic fields of magneto-rotational instability definitely show the presence of two-armed spiral structure in the quasi-steady state of accretion disks. In such deformed disks, two-armed ($m=2$) c-mode ($n=1$) oscillations are excited by wave–wave resonant instability. Among these excited oscillations, the fundamental in the radial direction ($n_{\rm r}=0$) will be the higher kHz QPO of twin QPOs, and the first overtone ($n_{\rm r}=1$) in the radial direction will be the lower kHz QPO of the twin. A possible cause of the twin high-frequency QPOs in black hole X-ray binaries is also discussed in the final section.

scholarly journals Modeling He-Rich Disks in AM CVn Binaries

2004 ◽  
Vol 194 ◽  
pp. 228-228
Author(s):  
T. Nagel ◽  
S. Dreizler ◽  
T. Rauch ◽  
K. Werner
Keyword(s):  
Accretion Disk ◽  
Time Scales ◽  
Accretion Disks ◽  
White Dwarf ◽  
Cataclysmic Variables ◽  
X Ray ◽  
Synthetic Spectra ◽  
Pure Helium ◽  
Low Mass ◽  
X Ray Binaries

We have developed a new code for the calculation of synthetic spectra and vertical structures of accretion disks in cataclysmic variables and compact X-ray binaries. Here we present results for the CV system AM CVn.AM CVn stars are a special type of cataclysmic variables, also called helium cataclysmics. They are systems of interacting binary white dwarfs, consisting of a degenerate C-O white dwarf primary and a low mass semi-degenerate secondary. The secondary loses mass, almost, pure helium, to the primary, forming an accretion disk. They have all in common a helium-rich composition, analoguous to the hydrogen-rich cataclysmic variables. They show photometric variabilities on time scales of ~ 1000s, the prototype of the class, AM CVn, e.g. exhibits a variability of ~ 18 min (Nelemans et al. 2001).

Emission lines from X-ray-heated accretion disks in low-mass X-ray binaries

1994 ◽  
Vol 431 ◽  
pp. 273 ◽  
Author(s):  
Yuan-Kuen Ko ◽  
Timothy R. Kallman
Keyword(s):  
Accretion Disks ◽  
Emission Lines ◽  
X Ray ◽  
Low Mass ◽  
X Ray Binaries
Sign in / Sign up

Export Citation Format

Share Document