The Role of Energetic Jets in Late Stages of Stellar Evolution

TYPEAstrophysics Seminar
Speaker:Sagiv Shiber
Time:14:30 - 15:30
Location:Lidow 620

In my PhD, I connect between jets, a common phenomena in many astrophysical objects, and some puzzling processes in late stages of stellar evolution. One of the least understood processes in stellar binary evolution, despite much progress, is the common envelope evolution. I conduct three-dimensional hydrodynamical simulations, and show that when a secondary star launches jets while interacting with a primary giant star in a close orbit, the jets facilitate the removal of the common envelope. I assume that the secondary star accretes mass via an accretion disk and that the accretion disk launches the jets. The results indicate that the jets eject most of the envelope gas and unbind a part of it. The jets produce high velocity outflow in the polar directions that can be as massive as the equatorial outflow. When comparing simulations with and without jets, the final orbital separation is larger and the orbit is more eccentric when jets are included. These results show that jets might solve some puzzles in the theory of common envelope evolution, namely the ejection of the envelope and the shaping of the outflow.