Colliding-wind Binaries with strong magnetic fields

Abstract

The dynamics of colliding wind binary systems and conditions for efficient particle acceleration therein have attracted multiple numerical studies in the recent years. These numerical models seek an explanation of the thermal and non-thermal emission of these systems as seen by observations. In the non-thermal regime, radio and X-ray emission is observed for several of these colliding-wind binaries, while gamma-ray emission has so far only been found in $\eta$ Carinae and possibly in WR 11. Energetic electrons are deemed responsible for a large fraction of the observed high-energy photons in these systems. Only in the gamma-ray regime there might be, depending on the properties of the stars, a significant contribution of emission from neutral pion decay. Thus, studying the emission from colliding-wind binaries requires detailed models of the acceleration and propagation of energetic electrons. This in turn requires a detailed understanding of the magnetic field, which will not only affect the energy losses of the electrons but in case of synchrotron emission also the directional dependence of the emissivity. In this study we investigate magnetohydrodynamic simulations of different colliding wind binary systems with magnetic fields that are strong enough to have a significant effect on the winds. Such strong fields require a detailed treatment of the near-star wind acceleration zone. We show the implementation of such simulations and discuss results that demonstrate the effect of the magnetic field on the structure of the wind collision region.

24 pages, 7 figures, accepted for publication in The Astrophysical Journal

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Cited by in corpus (10)

• Colliding Stellar Winds Structure and X-ray Emission
• The CRONOS Code for Astrophysical Magnetohydrodynamics
• 3D magneto-hydrodynamic models of non-thermal photon emission in the binary system ${\gamma }^2$ Velorum
• Simulating observable structures due to a perturbed interstellar medium in front of astrospheric bow shocks in 3D MHD
• Proton acceleration in colliding stellar wind binaries
• PION: Simulating bow shocks and circumstellar nebulae
• The interaction of multiple stellar winds in stellar clusters: potential flow
• Colliding-Wind Binaries as a Source of TeV Cosmic Rays
• High Energy Processes in Wolf-Rayet Stars
• Limits on the non-thermal emission of the WR-WR system Apep