X-Ray Bubbles

Central stars of planetary nebulae and Wolf-Rayet stars have energetic fast stellar winds, with velocities easily >1,000 km/s. These winds sweep up the material around the star ejected in previous phases of the stellar evolution and blow circumstellar bubbles. Similarly, the combined wind of young, pre-supernova OB associations blows a bubble. In the interaction between the fast stellar wind and the circumstellar material, the fast wind is shock-heated to high temperatures in excess of 10^6 K and the thermal pressure inside the central cavity drives the expansion of these bubbles. Therefore, the shocked stellar wind plays a crucial role in the formation and evolution of circumstellar bubbles. This hot gas can be studied through its X-ray emission, but observations have been hampered by the limited sensitivity and spatial resolution of previous X-ray missions. Chandra and XMM-Newton unprecedented sensitivity and spatial and spectral resolution allows us to study in detail for the first time the hottest component of circumstellar bubbles.

 

Fecha: 
03/12/2003 - 13:00
Conferenciante: 
Martín Guerrero Roncel
Filiación: 
Instituto de Astrofísica de Andalucía - CSIC


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