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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

MHD numerical simulations of colliding winds in massive binary systems - I. Thermal versus non-thermal radio emission

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Falceta-Goncalves, D. [1] ; Abraham, Z. [2]
Total Authors: 2
[1] Univ Sao Paulo, Escola Artes Ciencias & Humanidades, BR-03828000 Sao Paulo - Brazil
[2] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, BR-05508900 Sao Paulo - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Monthly Notices of the Royal Astronomical Society; v. 423, n. 2, p. 1562-1570, JUN 2012.
Web of Science Citations: 15

In the past few decades detailed observations of radio and X-ray emission from massive binary systems revealed a whole new physics present in such systems. Both thermal and non-thermal components of this emission indicate that most of the radiation at these bands originates in shocks. O and B-type stars and WolfRayet (WR) stars present supersonic and massive winds that, when colliding, emit largely due to the freefree radiation. The non-thermal radio and X-ray emissions are due to synchrotron and inverse Compton processes, respectively. In this case, magnetic fields are expected to play an important role in the emission distribution. In the past few years the modelling of the freefree and synchrotron emissions from massive binary systems have been based on purely hydrodynamical simulations, and ad hoc assumptions regarding the distribution of magnetic energy and the field geometry. In this work we provide the first full magnetohydrodynamic numerical simulations of windwind collision in massive binary systems. We study the freefree emission characterizing its dependence on the stellar and orbital parameters. We also study self-consistently the evolution of the magnetic field at the shock region, obtaining also the synchrotron energy distribution integrated along different lines of sight. We show that the magnetic field in the shocks is larger than that obtained when the proportionality between B and the plasma density is assumed. Also, we show that the role of the synchrotron emission relative to the total radio emission has been underestimated. (AU)

FAPESP's process: 11/12909-8 - Magnetic fields, turbulence and plasma effects in the intergalactic medium
Grantee:Diego Antonio Falceta Gonçalves
Support type: Regular Research Grants