EDP Sciences
Free access
Volume 399, Number 3, March I 2003
Page(s) 1121 - 1134
Section Stellar atmospheres
DOI http://dx.doi.org/10.1051/0004-6361:20021854

A&A 399, 1121-1134 (2003)
DOI: 10.1051/0004-6361:20021854

Gamma-ray emission from Wolf-Rayet binaries

P. Benaglia and G. E. Romero

Instituto Argentino de Radioastronomía, C.C.5, (1894) Villa Elisa, Buenos Aires, Argentina
(Received 14 May 2002 / Accepted 4 December 2002)

In the colliding wind region of early-type binaries, electrons can be accelerated up to relativistic energies displaying power-law spectra, as demonstrated by the detection of non-thermal radio emission from several WR+OB systems. The particle acceleration region, located between the stars, is exposed to strong photon fields in such a way that inverse Compton cooling of the electrons could result in a substantial high-energy non-thermal flux. In particular cases, the ratio of the energy densities of magnetic to photon fields in the colliding wind region will determine whether a given source can produce or not significant gamma-ray emission. We present here a study of the binaries WR 140, WR 146, and WR 147 in the light of recent radio and gamma-ray observations. We show that with reasonable assumptions for the magnetic field strength WR 140 can produce the gamma-ray flux from the EGRET source 3EG J2022+4317. WR 146 and WR 147 are below the detection threshold, but new and forthcoming instruments like INTEGRAL and GLAST might detect non-thermal emission from them.

Key words: stars: early-type -- stars: binaries: general -- stars: winds, outflows -- radio continuum: stars -- gamma-rays: observations -- gamma-rays: theory

Offprint request: P. Benaglia, paula@lilen.fcaglp.unlp.edu.ar

SIMBAD Objects

© ESO 2003

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access.

An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account.
    In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.