Interaction of the Stellar Wind with Circumstellar Matter in Eta Carinae.

With 3D hydrodynamical simulations I show that the asymmetric morphology of
the blue and red shifted components of the outflow at hundreds of AU from
the massive binary system eta Carinae can be explained by an interaction of
the primary stellar wind with the slowly expanding dense equatorial gas. I
performed 3D hydrodynamical simulations with the numerical code FLASH, and
produced a set of velocity component maps similar to the observed maps. The
dense circumstellar gas was ejected in an eruption that occured 115 years
ago, and it is concentrated toward us relative to the binary system. Hence,
my results strengthen the claim that for most of the time the primary star
is closer to us and the secondary is away from us in their highly eccentric
orbit around each other.