A 3D dynamical model of the colliding winds in binary systems

E. R. Parkin & J. M. Pittard

University of Leeds

We present a 3D dynamical model of the orbital induced curvature of
the wind-wind collision region in binary star systems. Momentum
balance equations are used to determine the position and shape of the
contact discontinuity between the stars, while further downstream the
gas is assumed to behave ballistically. An archimedean spiral
structure is formed by the motion of the stars, with clear resemblance
to high resolution images of the so-called ``pinwheel nebulae''. A key
advantage of this approach over grid or smoothed particle hydrodynamic
models is its significantly reduced computational cost, while it also
allows the study of the structure obtained in an eccentric orbit. The
model is relevant to symbiotic systems and Gamma-ray binaries, as
well as systems with O-type and Wolf-Rayet stars.

As an example application, we simulate the X-ray emission from
hypothetical O+O and WR+O star binaries, and describe a method of ray
tracing through the 3D spiral structure to account for absorption by
the circumstellar material in the system. Such calculations may be
easily adapted to study observations at wavelengths ranging from the
radio to Gamma-ray.

Reference: Accepted by MNRAS
Status: Manuscript has been accepted

Weblink: http://arxiv.org/abs/0805.4529

Comments: 16 pages, 24 figures

Email: erp@ast.leeds.ac.uk