Vacuum polarization effects on radiative opacities in a strong magnetic field

Journal Article · Fri Jun 15 00:00:00 EDT 1979 · Phys. Rev., D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.19.3565· OSTI ID:6209803

Meszaros, P; Ventura, J

We study the electromagnetic properties of plasmas allowing for the polarization effect of the vacuum induced by the presence of a strong external magnetic field. Adopting the cold-plasma polarization tensor to account for the electron component, we find that the polarization properties and transport of x-ray radiation can be severely altered by the magnetic vacuum effects. The effect becomes important at relatively high frequencies, ..omega../..omega../sub p/ > or approx. = (15..pi../..cap alpha..)/sup 1/2/ B/sub c//B where ..omega../sub p/ = (4..pi..n/sub e/ e/sup 2//m)/sup 1/2/ is the plasma frequency of the electron component, ..cap alpha.. is the fine-structure constant, and B/sub c/ = m/sup 2/c/sup 3//eh approx. = 4.4 x 10/sup 13/ G is the electrodynamic critical field. For typical pulsar magnetic fields, B approx. 0.1 B/sub c/, and x-ray frequencies, this condition is satisfied even for relatively high plasma densities n/sub e/ approx. 10/sup 23/ cm/sup -3/. Whenever the above inequality is fulfilled the vacuum effect dominates the polarization properties of the normal modes of the medium, giving rise to a significant change in the medium opacity. The Thomson, bremsstrahlung, and cyclotron opacities are thus significantly altered from their usual cold-plasma values. The largest departures are found in the vicinity of the electron gyrofrequency, where the vacuum induces a strongly anisotropic resonant behavior on the ordinary mode (which is nonresonant in the usual cold-plasma circumstances). This property may be significant in analyzing the polarization and spectral character of the cyclotron feature in Hercules X-1 and other accreting x-ray pulsars.

• Research Organization: Institut fuer Astrophysik, Max-Planck-Institut fuer Physik und Astrophysik, Foehringer Ring 6, 8 Muenchen 40, West Germany
• OSTI ID: 6209803
• Journal Information: Phys. Rev., D; (United States), Vol. 19:12
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COLD PLASMA
ELECTROMAGNETIC INTERACTIONS
VACUUM POLARIZATION
PULSARS
PLASMA DENSITY
BREMSSTRAHLUNG
CYCLOTRON FREQUENCY
ELECTRODYNAMICS
MAGNETIC FIELDS
MAGNETOSPHERE
BASIC INTERACTIONS
COSMIC RADIO SOURCES
EARTH ATMOSPHERE
ELECTROMAGNETIC RADIATION
INTERACTIONS
PLASMA
RADIATIONS
700103* - Fusion Energy- Plasma Research- Kinetics