ROSAT observations of the Orion-Eridanus Superbubble.
Abstract
The Orion-Eridanus Bubble is a large nearby superbubble created by the Orion OB1 stellar association. X-ray emission from the interior of this superbubble, which has a temperature of about 1.2 million degrees, forms a prominent feature of the soft X-ray diffuse background extending across roughly 20°×35° on the sky. ROSAT All-Sky Survey maps of this object show evidence of numerous soft X-ray shadows cast by neutral foreground clouds against the bright emission of the superbubble interior. Using ROSAT pointed observations, 21 cm maps, and optical absorption line measurements, the authors have identified the velocities of some of these absorbing clouds and have placed distance limits on them. These in turn allow to place constraints on a three-dimensional model of this superbubble and to improve the estimates of the energetics and evolution of the superbubble. The data are consistent with a model for this superbubble in which the structure is formed by stellar winds but has been most recently re-energized about 1.2×105yr ago by a supernova, possibly associated with a runaway star from the Orion OB1 association. In addition, the authors have identified absorption features associated with the shell of the Local Bubble, enabling to place constraints on its distance in this direction and to obtain an accurate measurement of the thermal pressure of the hot gas in this direction.
- Publication:
-
Roentgenstrahlung from the Universe
- Pub Date:
- February 1996
- Bibcode:
- 1996rftu.proc..221B
- Keywords:
-
- X-Ray Background: OB Associations;
- X-Ray Background: Interstellar Bubbles;
- OB Associations: Interstellar Bubbles;
- OB Associations: Stellar Winds;
- X-Ray Background: Supernova Remnants