Stark-broadened Emission Lines in the Accretion Disks of Cataclysmic Variables
Abstract
The frequent occurrence of double-peaked emission-line profiles in cataclysmic variables is generally interpreted as due to Doppler broadening caused by the Keplerian motion in geometrically thin accretion disks around white dwarfs. However, single-peaked profiles are frequently observed in many eclipsing systems that are viewed edge-on. Furthermore, broad wings are also present in some low-inclination systems that are observed nearly face-on. Simplified calculations for idealized disk models are presented that demonstrate that these features can be attributed to the Stark effect. Using these models, it is shown that the emission lines are generated over regions with temperatures 6000-9000 K and densities 10 to the 14th-17th/cu cm. From these parameters, the mass transfer rate and effective viscosity in the disk during the quiescent state can be deduced. Finally, it is shown that the evolution of emission-line profiles through eclipse can reveal basic parameters of the disk structure such as the temperature and surface density distribution.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1988
- DOI:
- 10.1086/166185
- Bibcode:
- 1988ApJ...327..234L
- Keywords:
-
- Accretion Disks;
- Cataclysmic Variables;
- Emission Spectra;
- Line Spectra;
- Stark Effect;
- White Dwarf Stars;
- Binary Stars;
- Computational Fluid Dynamics;
- Doppler Effect;
- High Temperature;
- Spatial Distribution;
- Stellar Spectra;
- Astrophysics;
- LINE PROFILES;
- STARS: ACCRETION;
- STARS: DWARF NOVAE;
- STARS: EMISSION-LINE