Jane Arthur, IRyA
Host: Ramandeep Gill
Tracing the Origins of Runaway Wolf-Rayet Stars in the Galaxy
Runaway massive stars are the result of dynamical ejection during the
formation process of young star-forming regions or the disruption of a
close binary system when the more massive component explodes as a
supernova. Runaway stars can be identified by their high peculiar
velocities and/or their large z-heights above the Galactic plane. In
the current paradigm for massive star evolution, classical Wolf-Rayet
stars are the descendants of O stars with initial masses above 25 solar
masses and have lifetimes less than 7 million years. In this talk, I
describe how Gaia DR3 astrometric data is used to identify runaway
Wolf-Rayet stars in the Galaxy. The trajectories of the runaways are then
integrated backwards in time in order to infer kinematical ages and
possible ejection mechanisms. I analyse the differences that are found in
the spatial distributions and kinematical ages of runaways with different
Wolf-Rayet subtypes. A few sources have inferred kinematic ages in excess
of 7 million years, suggesting that binary evolution has played a
significant role in their lives. I discuss the runaway frequency and
characteristics in the context of stellar evolution models.