Colliding-Wind Binary

A Colliding - Wind Binary (English translation binary with colliding stellar winds ) is an interactive binary star consisting of two early stars, whose stellar wind collides with high speed and produced in the collision zone radio, X-ray and gamma radiation.

Early star with spectral type O and Wolf- Rayet stars produce stellar winds with velocities of a few 1000 km / s and mass loss rates up to 10-3 solar masses per year. There are two such stars in a close binary system with short durations of not more than 10 days, some forms between them a shock front of, be in the braked the accelerated particles and heated to temperatures of up to 108 K. The resulting bremsstrahlung and heat radiation reaches the X-ray luminosities of 1032 to 1034 erg / s The X-ray radiation is variable due to the inhomogeneous structure of the stellar wind, the varying line of sight to the observer during the path circulation as well as the fluctuating case of elliptical orbits distance between the stars.

In addition to thermal radiation in the radio and X-ray evidence of non-thermal emission have been discovered. The gamma radiation is definitely not thermal in nature and could in electron -positron pair production with subsequent acceleration of the particles in the magnetic field generated in the wind collision zone. Other sources of gamma radiation could be pion decay and Compton scattering. The radio emission is likely to be generated mainly by synchrotron radiation.

Colliding - wind binaries are not included among the X-ray binaries, since the radiated energy is not derived from the acceleration in a gravitational field.

Examples

  • V444 Cygni
  • Gamma 2 Velorum
  • WR 140
  • Eta Carinae

Sources

  • M. De Becker, F. Raucq: Catalogue of particle -accelerating colliding - wind binaries. In: Astrophysics. Solar and Stellar Astrophysics. 2013, arXiv: 1308.3149v1.
  • M. Werner, O. Reimer, A. Reimer, K. Egberts: Fermi -LAT upper limits on gamma -ray emission from colliding wind binaries. In: Astrophysics. Solar and Stellar Astrophysics. 2013, arXiv: 1308.2573v1.
  • Astrid Lambert, Guillaume Dubus, Sebastien Fromang, Geoffroy Lesur: Colliding wind binaries and gamma -ray binaries: relativistic version of the RAMSES code. In: Astrophysics. Solar and Stellar Astrophysics. 2012, arXiv: 1212.4142v1.
  • Marc Gagne, Garrett Fehon, Michael Savoy, Carlos Cartagena, David H. Cohen, Stanley P. Owocki: An X -ray Survey of Colliding Wind Binaries. In: Astrophysics. Solar and Stellar Astrophysics. 2012, arXiv: 1205.3510v2.
  • Star class
Interacting binary star O-type main-sequence star Wolf–Rayet star
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