Nonthermal radio emission from RS CVN binaries and similar systems
Enhanced emission at radio, optical, and X-ray frequencies appears to be a characteristic feature of late-type stars in close binary systems. The emission is thought to originate through an enhanced dynamo mechanism caused by rapid differential rotation in the stellar convective zone. Here the author presents a large scale study of such systems, and a two dimensional magnetospheric model which reproduces many of the observed properties. The radio emission consists of two components: (1) a slowly varying, moderately circularly polarized component and (2) short duration flares. The former is well modeled by gyrosynchrotron emission from mildly relativistic electrons in an inhomogeneous plasma. A large scale VLA survey of 103 close binaries detected 53 systems at 5 GHz with fluxes above the minimum detectable flux of 0.4 mJy. The mean 5 GHz radio luminosity of all detected systems was log L{sub r} = 16.7 erg sec{sup {minus}1} Hz{sup {minus}1}, but analysis by distance interval indicates that the mean luminosity for the parent population must be log L{sub r} {approx lt} 15. The implications that these observations have for modeling the physical environment from which the emission arises are discussed and a detailed two dimensional model presented. The model calculations integrate the equation of radiative transfer along lines of sight with varying impact parameters through a single magnetospheric cut defined by the ray paths and the magnetic field axis. The angle of this axis to the line of sight is an adjustable parameter. The emergent spectral and polarization characteristics are presented and compared to the observations.
- Research Organization:
- Iowa Univ., Iowa City, IA (USA)
- OSTI ID:
- 5220779
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
BINARY STARS
BREMSSTRAHLUNG
CONVECTION
CORRELATIONS
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
ENERGY RANGE
ENERGY TRANSFER
FERMIONS
HEAT TRANSFER
IONIZING RADIATIONS
LEPTONS
MASS TRANSFER
MATHEMATICAL MODELS
MOTION
POLARIZATION
RADIATION TRANSPORT
RADIATIONS
RADIOWAVE RADIATION
RELATIVISTIC RANGE
ROTATION
STAR MODELS
STARS
STELLAR ACTIVITY
STELLAR ATMOSPHERES
STELLAR FLARES
STELLAR MAGNETOSPHERES
SYNCHROTRON RADIATION
TWO-DIMENSIONAL CALCULATIONS
VISIBLE RADIATION
X RADIATION