Vacuum polarization effects on radiative opacities in a strong magnetic field

Journal Article · Fri Jun 15 04:00:00 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), Journal Name: Phys. Rev., D; (United States) Vol. 19:12; ISSN PRVDA
• Country of Publication: United States
• Language: English

Related Subjects

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