Accretion at the periastron passage of Eta Carinae

We present high-resolution numerical simulations of the colliding wind system η Carinae, showing accretion on to the secondary star close to periastron passage. Our hydrodynamical simulations include self-gravity and radiative cooling. The smooth stellar winds collide and develop instabilities, mainly the non-linear thin shell instability, and form filaments and clumps. We find that a few days before periastron passage the dense filaments and clumps flow towards the secondary as a result of its gravitational attraction, and reach the zone where we inject the secondary wind. We run our simulations for the conventional stellar masses, M₁ = 120M_⊙ and M₂ = 30M_⊙, and for a high mass model, M₁ = 170M_⊙ and M₂ = 80M_⊙, that was proposed to better fit the history of giant eruptions. As expected, the simulations results show that the accretion processes are more pronounced for a more massive secondary star.