Einstein observations of EF Eridani (2A 0311-227) - the textbook example of AM Herculis-type systems

Journal Article · Fri May 01 04:00:00 EDT 1987 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/165206· OSTI ID:6210595

Beuermann, K; Stella, L; Patterson, J

Hard and soft X-ray spectra of the AM Herculis star EF Eridani obtained with the Einstein Observatory are found to be fitted by a thermal bremsstrahlung spectrum with kT of about 20 keV, and a blackbody spectrum with kT of between 16 and about 33 eV, respectively. EF Eri is shown to behave almost exactly as predicted by simple theory, with its soft X-ray luminosity not exceeding the hard X-ray luminosity by more than a factor of three, and both spectra originating from the same active pole of the accreting white dwarf. The data are consistent with a model involving an accretion stream penetrating deep into the magnetosphere of the white dwarf, such that accretion occurs along nonpolar field lines, and an 'X-ray auroral oval' emission is formed on the surface of the white dwarf. 52 references.

• Research Organization: Max-Planck-Institut fuer extraterrestrische Physik, Garching, West Germany; EXOSAT Observatory, Darmstadt, West Germany; Harvard-Smithsonian Center for Astrophysics, Cambridge; Columbia Univ., New York; Harvard-Smithsonian Center for Astrophysics, Cambridge, MA
• OSTI ID: 6210595
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 316; 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
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
CYCLOTRON RADIATION
DWARF STARS
ELECTROMAGNETIC RADIATION
HARD X RADIATION
IONIZING RADIATIONS
LUMINOSITY
MAGNETIC FIELDS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATIONS
SOFT X RADIATION
SPECTRA
STAR ACCRETION
STAR EVOLUTION
STARS
STELLAR ATMOSPHERES
WHITE DWARF STARS
X RADIATION
X-RAY SPECTRA