Effects of stellar evolution and ionizing radiation on the environments of massive stars

Abstract

We discuss two important effects for the astrospheres of runaway stars: the propagation of ionizing photons far beyond the astropause, and the rapid evolution of massive stars (and their winds) near the end of their lives. Hot stars emit ionizing photons with associated photoheating that has a significant dynamical effect on their surroundings. 3D simulations show that HII regions around runaway O stars drive expanding conical shells and leave underdense wakes in the medium they pass through. For late O stars this feedback to the interstellar medium is more important than that from stellar winds. Late in life, O stars evolve to cool red supergiants more rapidly than their environment can react, producing transient circumstellar structures such as double bow shocks. This provides an explanation for the bow shock and linear bar-shaped structure observed around Betelgeuse.

arXiv comment5 pages, 2 figures, conference proceedings in "Wind Bubbles, Astrospheres and the Heliosphere: Environments and Cosmic Rays", Bochum, Germany (Nov 2013). Published in ASTRA proceedings, an Open Access Journal for Refereed Proceedings in Extraterrestrial Research

References in corpus (6)

• Massive stars and the energy balance of the ISM. I. The impact of an isolated 60 Msun star
• The enigmatic nature of the circumstellar envelope and bow shock surrounding Betelgeuse as revealed by Herschel. I. Evidence of clumps, multiple arcs, and a linear bar-like structure
• 3D Simulations of Betelgeuse's Bow Shock
• Double bow shocks around young, runaway red supergiants: application to Betelgeuse
• Dynamics of H II regions around exiled O stars
• Zeta Oph and the weak-wind problem

Cited by in corpus (4)

• PARSEC evolutionary tracks of massive stars up to $350M_{\odot }$ at metallicities 0.0001$\le Z\le$0.04
• MHD-shock structures of astrospheres: $\lambda$ Cephei-like astrospheres
• Shock structures of astrospheres
• Particle acceleration, escape and non-thermal emission from core-collapse supernovae inside non-identical wind-blown bubbles