Emission lines from the accretion disks of cataclysmic variables

1980 ◽  
Vol 235 ◽  
pp. 939 ◽  
Author(s):  
R. E. Williams
1988 ◽  
Vol 327 ◽  
pp. 234 ◽  
Author(s):  
D. N. C. Lin ◽  
R. E. Williams ◽  
R. J. Stover

2006 ◽  
Vol 2 (S238) ◽  
pp. 475-476
Author(s):  
Alexander F. Zakharov

AbstractRecent X-ray observations of microquasars and Seyfert galaxies reveal broad emission lines in their spectra, which can arise in the innermost parts of accretion disks. Recently Müller & Camenzind (2004) classified different types of spectral line shapes and described their origin. Zakharov (2006b) clarified their conclusions about an origin of doubled peaked and double horned line shapes in the framework of a radiating annulus model and discussed s possibility to evaluate black hole parameters analyzing spectral line shapes.


1986 ◽  
Vol 64 (4) ◽  
pp. 501-506 ◽  
Author(s):  
Ralph E. Pudritz ◽  
Colin A. Norman

We present a hydromagnetic wind model for molecular and ionized gas outflows associated with protostars. If the luminosity of protostars is due to accretion, then centrifugally driven winds that arise from the envelopes of molecular disks explain the observed rates of momentum and energy transport. Ionized outflow originates from disk radii r ≤ 1015 cm inside of which Ly-continuum photons from the protostellar accretion shock are intercepted. Observed molecular outflows arise from the cool disk envelope at radii 1015 ≤ r ≤ 1017 cm. The mass-loss rates of these two component outflows are [Formula: see text] and [Formula: see text]. These winds solve the angular-momentum problem of star formation. We propose that the collimation of such outflows is due to "hoop" stresses generated by the increasingly toroidal magnetic field in the wind and suggest that the structure of the underlying disks makes self-similar solutions for these outflows likely. Finally, we apply this analysis to other accreting systems such as cataclysmic variables.


2015 ◽  
Vol 2 (1) ◽  
pp. 41-45
Author(s):  
S. Zharikov ◽  
G. Tovmassian

We discussed features of Cataclysmic Variables at the period minimum. In general, most of them must be WZ Sge-type objects. Main characteristics of the prototype star (WZ Sge) are discussed. A part of WZ Sge-type objects has evolved past the period limit and formed the bounce back systems. We also explore conditions and structure of accretion disks in such systems. We show that the accretion disk in a system with extreme mass ratio grows in size reaching a 2:1 resonance radius and are relatively cool. They also become largely optically thin in the continuum, contributing to the total flux less than the stellar components of the system. In contrast, the viscosity and the temperature in spiral arms formed at the outer edge of the disk are higher and their contribution in continuum plays an increasingly important role. We model such disks and generate light curves which successfully simulate the observed double-humped light curves in the quiescence.


2001 ◽  
Vol 45 (9) ◽  
pp. 676-685 ◽  
Author(s):  
D. V. Bisikalo ◽  
A. A. Boyarchuk ◽  
A. A. Kilpio ◽  
O. A. Kuznetsov

1991 ◽  
Vol 374 ◽  
pp. L55 ◽  
Author(s):  
Keith Horne ◽  
Steven H. Saar

1982 ◽  
Vol 69 ◽  
pp. 219-230 ◽  
Author(s):  
G. Hensler

AbstractA numerical method for 3D magnetohydrodynamical investigations of accretion disks in close binary systems is presented, which allows for good spatial resolution of structures (hot spot, accretion column). The gas is treated as individual gas cells (pseudo-particles) whose motion is calculated within a grid consisting of one spherical inner part for 3D MHD and two plane outer parts. Viscous interactions of the gas cells are taken into account by a special treatment connected with the grid geometry.We present one result of 2D hydrodynamical calculations for a binary applying the following parameters which are representative for Cataclysmic Variables: M1 = 1 Mʘ, r1 = 10-2 Rʘ, M2 = 0.5 Mʘ, p = 0.2 d, M = 10-9 Mʘ y-1.Column density and radiative flux distributions over the disk are shown and briefly discussed by comparison with the theoretical understanding of these Dwarf Novae drawn from observations.


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