Wind-Blown Bubbles around Evolved Stars

Abstract

Most stars will experience episodes of substantial mass loss at some point in their lives. For very massive stars, mass loss dominates their evolution, although the mass loss rates are not known exactly, particularly once the star has left the main sequence. Direct observations of the stellar winds of massive stars can give information on the current mass-loss rates, while studies of the ring nebulae and HI shells that surround many Wolf-Rayet (WR) and luminous blue variable (LBV) stars provide information on the previous mass-loss history. The evolution of the most massive stars, (M > 25 solar masses), essentially follows the sequence O star to LBV or red supergiant (RSG) to WR star to supernova. For stars of mass less than 25 solar masses there is no final WR stage. During the main sequence and WR stages, the mass loss takes the form of highly supersonic stellar winds, which blow bubbles in the interstellar and circumstellar medium. In this way, the mechanical luminosity of the stellar wind is converted into kinetic energy of the swept-up ambient material, which is important for the dynamics of the interstellar medium. In this review article, analytic and numerical models are used to describe the hydrodynamics and energetics of wind-blown bubbles. A brief review of observations of bubbles is given, and the degree to which theory is supported by observations is discussed.

To be published as a chapter in 'Diffuse Matter from Star Forming Regions to Active Galaxies' - A volume Honouring John Dyson. Eds. T. W. Harquist, J. M. Pittard and S. A. E. G. Falle. 22 pages, 12 figures

References in corpus (3)

• Constraints on gamma-ray burst and supernova progenitors through circumstellar absorption lines
• Photoevaporation Flows in Blister HII Regions: I. Smooth Ionization Fronts and Application to the Orion Nebula
• X-ray Emission from Wind Blown Bubbles. III. ASCA SIS Observations of NGC6888

Cited by in corpus (9)

• Radiation-Hydrodynamic Models of the evolving Circumstellar Medium around Massive Stars
• The three dimensional dynamic structure of the inner Orion Nebula
• Dusty Wind-Blown Bubbles
• Massive star cluster formation I. High star formation efficiency while resolving feedback of individual stars
• On the diffuse X-ray emission from the Wolf-Rayet Bubble NGC 2359
• Star formation activity in the neighbourhood of W-R 1503-160L star in the mid-infrared bubble N46
• Carbon monoxide in the environs of the star WR 16
• Molecular gas towards G18.8+1.8
• NANTEN 12CO (J=1-0) observations around the star WR 55