Polarized radiation from hot plasmas and applications to AM herculis binaries. II. Effect of collisions and thomson scattering

Journal Article · Thu Mar 01 04:00:00 EST 1984 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/161794· OSTI ID:6663957

Barrett, P E; Chanmugam, G

The absorption coefficients in the ordinary and extraordinary modes are calculated, for radiation emitted by magnetoactive plasmas with temperatures in the range 0.1--5 keV. The equations of radiative transfer for a homogeneous plasma, with large Faraday rotation, are solved, and simple analytic expressions for the Stokes parameters Q and V are derived in terms of the optical depths in the ordinary and extraordinary modes. The results are applied to homogeneous plasma slabs which represent a simple model for the accretion columns of the AM Herculis binaries. It is shown that the inclusion of the effects of collisions and Thomson scattering reduces the amount of fractional polarized radiation, bringing better agreement with observations. For small viewing angles with the magnetic field the circular polarization does not approach 100% as in the collisionless case, but instead approaches 0% or a value less than 100% depending on the geometry. This may provide a qualitative explanation for the standstills observed in some AM Her binaries.

• Research Organization: Department of Physics and Astronomy, Louisiana State University, Baton Rouge; and Los Alamos National Laboratory
• OSTI ID: 6663957
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 278:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTIVITY
BINARY STARS
BREMSSTRAHLUNG
COLLISIONS
ELECTROMAGNETIC RADIATION
ELECTRON COLLISIONS
ELECTRON-ION COLLISIONS
FARADAY EFFECT
HOT PLASMA
ION COLLISIONS
JOULE-THOMSON EFFECT
MAGNETIC FIELDS
MATHEMATICAL MODELS
MOTION
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PLASMA
POLARIZATION
RADIATION TRANSPORT
RADIATIONS
ROTATION
STAR ACCRETION
STAR EVOLUTION
STAR MODELS
STARS
STELLAR RADIATION
STOKES PARAMETERS
VARIABLE STARS