Polarized radiation in magnetic white dwarfs

Journal Article · Mon Nov 01 04:00:00 EST 1976 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/154786· OSTI ID:7338111

Rosi, L A; Zimmerman, R L; Kemp, J C

A model for magnetic white dwarfs is proposed which attributes the partially polarized light to synchrotron radiation. The source of the radiation is relativistic electrons trapped in the magnetosphere of a white dwarf. The white dwarf's magnetic field is assumed to be dipolar. The Stokes parameters for the synchrotron radiation are tabulated as a function of frequency, observer's orientation, and energy and spatial distribution of the relativistic electrons. The results of the synchrotron calculations are applied to the polarization observations of Grw+70degree8247 and DQ Herculis. This model can account for the major features of the polarized radiation coming from these two magnetic white dwarfs. The calculations predict for Grw+70degree8247 that the surface magnetic field is B/sub s/approximately-less-than4 x 10/sup 6/ gauss, that the incident viewing angle is 45degreeapproximately-less-thantheta/sub 0/approximately-less-than75degree, and that the electrons are trapped with nearly an isotropic distribution about the white dwarf. For DQ Herculis the surface magnetic field is B/sub s/approximately-less-than7 x 10/sup 6/ gauss and the trapped electrons are confined to a dislike region about the white dwarf. For both cases the density of electrons in the magnetosphere falls in the range of 10/sup 5/approximately-less-thannapproximately-less-than10/sup 7/ cm/sup -3/ with energies of about 4--35 MeV. (AIP)

• Research Organization: Department of Physics and Institute of Theoretical Science, University of Oregon
• OSTI ID: 7338111
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 209:3; 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
ATMOSPHERES
BINARY STARS
BREMSSTRAHLUNG
DWARF STARS
ELECTROMAGNETIC RADIATION
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELDS
MAGNETIC STARS
PLASMA
POLARIZATION
RADIATIONS
RELATIVISTIC PLASMA
STARS
STELLAR ATMOSPHERES
STELLAR MAGNETOSPHERES
STOKES PARAMETERS
SYNCHROTRON RADIATION
WHITE DWARF STARS