Wolf-Rayet Bubbles. I. Analytic Solutions

Abstract

view Abstract Citations (99) References (53) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Wolf-Rayet Bubbles. I. Analytic Solutions Garcia-Segura, Guillermo ; Mac Low, Mordecai-Mark Abstract Stellar wind bubble dynamics are sensitive to the stellar wind velocity and mass-loss history. Observations of ring nebulae can thus strongly constrain theories of stellar winds and massive stellar evolution. Furthermore, ring nebulae are often observed around Wolf-Rayet stars likely to soon become supernovae, so their influence on the circumstellar medium is vital to understanding young supernova remnants such as Cas A. To interpret the observations, the connection between the input wind and the observed gas distribution must be described. This is our goal in this series of papers. In this paper, we present analytic solutions for the dynamics of bubbles expanding into media with power-law density distributions such as r-2. We apply the solutions to Wolf-Rayet bubbles expanding into red supergiant winds. A semianalytic method is used to model aspherical bubbles resulting from nonspherical red supergiant winds. Applying this method, we find, for the case of steady winds, that bubbles expand at nearly constant velocity in each direction, keeping their shapes. We can then make the approximation that the bubbles have constant-eccentricity ellipsoidal shapes to derive a fully analytic dynamical model. From this we derive solutions for the diffuse X-ray luminosities from steady winds, using the assumption of classical conductive evaporation. Useful relationships between observables are also given. The solutions are compared to observations of the Wolf-Rayet ring nebula NGC 6888. We find that with either the assumption of energy conservation or momentum conservation, the dynamics of this nebula cannot be explained if the reported wind kinetic energy of the central star WR 136 is used. The nebular kinematics require an order of magnitude less effective mechanical luminosity from WR 136, demanding a lower mass-loss rate, a lower wind velocity, or both. Publication: The Astrophysical Journal Pub Date: December 1995 DOI: 10.1086/176563 Bibcode: 1995ApJ...455..145G Keywords: ISM: BUBBLES; ISM: INDIVIDUAL NGC NUMBER: NGC 6888; ISM: STRUCTURE; STARS: MASS LOSS; STARS: WOLF-RAYET full text sources ADS | data products SIMBAD (4) Related Materials (1) Part 2: 1995ApJ...455..160G