Document Type
Article
Publication Date
1987
Abstract
Stellar winds and repeated supernovae from an OB association will create a cavity of coronal gas in the interstellar medium, with radius greater than 100 pc, surrounded by a dense, expanding shell of cool interstellar gas. If the association has a typical initial mass function, its supernovae explosions will inject energy into the supershell at a nearly constant rate for about 5 x 10^7 yr. The supershell loses its interior pressure and enters the snowplow phase when radiative cooling becomes important or when the shell bursts through the gas disk of a galaxy, typically after a few times 10^7 yr and with a radius -100-300 pc. At approximately the same time, the supershell becomes gravitationally unstable, forming giant molecular clouds which are sites for new star formation. There is widespread evidence for supershells in the Milky Way and other spiral and irregular galaxies from 21 cm emission-line surveys, optical emission-line surveys, and studies of supernova remnants. The gravitational instability of the supershells provides a physical mechanism for induced star formation and may account for bursts of star formation, especially in irregular galaxies.
Recommended Citation
McCray, R., Kafatos, M. (1987) Supershells and Propagating Star Formation, The Astrophysical Journal, 317: 190-196. doi: 10.1086/165267
Peer Reviewed
1
Copyright
IOP Publishing
Comments
This article was originally published in Astrophysical Journal, volume 317, in 1987. DOI: 10.1086/165267