Nonthermal X-ray emission from winds of OB supergiants
- Johns Hopkins Univ., MD (USA) Space Telescope Science Institute, Baltimore, MD (USA)
The mechanisms responsible for the hard X-ray emission of OB supergiants (OBSGs) are investigated theoretically, modifying the periodic-shock model of Lucy (1982). The physical processes discussed include (1) the particle acceleration (PA) mechanism and its effect on the structure of individual shocks, (2) the energy cutoff and spectral index of the relativistic electrons and ions, and (3) the efficiency of PA by shocks and its implications for the number densities of relativistic particles. The model is used to predict the spectrum and intensity of the dominant nonthermal X-ray emission source from OBSGs, and the results are shown to be in good agreement with Einstein Observatory Solid-State Spectrometer observations of three OBSGs in Orion (Cassinelli and Swank, 1983). It is inferred that the surface magnetic fields of OBSGs are no greater than a few G, and that the PA rates are significantly lower than generally predicted for collisionless astrophysical shocks. 66 refs.
- OSTI ID:
- 5995287
- Journal Information:
- Astrophysical Journal; (USA), Vol. 366; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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NONTHERMAL RADIATION FROM COSMIC-RAY MODIFIED SHOCKS
Related Subjects
GENERAL PHYSICS
SUPERGIANT STARS
HARD X RADIATION
STAR MODELS
ACCELERATION
COMPARATIVE EVALUATIONS
COMPTON EFFECT
GAMMA RADIATION
MAGNETIC FIELDS
MAGNETIC STARS
RADIOWAVE RADIATION
SHOCK WAVES
STELLAR RADIATION
STELLAR WINDS
WOLF-RAYET STARS
BASIC INTERACTIONS
ELASTIC SCATTERING
ELECTROMAGNETIC INTERACTIONS
ELECTROMAGNETIC RADIATION
GIANT STARS
INTERACTIONS
IONIZING RADIATIONS
MAIN SEQUENCE STARS
MATHEMATICAL MODELS
RADIATIONS
SCATTERING
STARS
STELLAR ACTIVITY
X RADIATION
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources