Detalles de publicación
PP 025004
The IACOB project XIII. Helium enrichment in O-type stars as a tracer of past binary interaction
(1) Instituto de Astrofísica de Canarias, c/Vía Láctea, s/n, E-38205 La Laguna, Tenerife, Spain
(2) Departamento de Astrofísica, Universidad de La Laguna, E-38206 La Laguna, Tenerife, Spain
(3) Argelander Institut für Astronomie, Auf dem Hügel 71, DE-53121 Bonn, Germany
(4) Center for Computational Astrophysics, Division of Science, National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588, Japan
(5) Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, DE-53121 Bonn, Germany
(6) LMU Munich, Universitätssternwarte, Scheinerstrasse 1, 81679 München, Germany
Abstract:There is increasing evidence that single-star evolutionary models are inadequate to reproduce all observational properties of massive stars. Binary interaction has emerged as a key factor in the evolution of a significant fraction of massive stars. In this study, we investigate the helium ($Y_{mathrm He}$) and nitrogen ($epsilon_{mathrm N}$) surface abundances in a comprehensive sample of 180 Galactic O-type stars with projected rotational velocities $vsin(i)leq150{mathrm km}cdot{mathrm s}^{-1}$. We found a subsample ($sim20%$ of the total, and $sim80%$ of the stars with $Y_{mathrm He}geq0.12$) with a $Y_{mathrm He}$ and $epsilon_{mathrm N}$ combined pattern unexplainable by single-star evolution. We argue that the stars with anomalous surface abundance patterns are binary interaction products.