Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

A threshold for sequentially self-propagating star formation

Whitworth, Anthony Peter and Francis, N. 2002. A threshold for sequentially self-propagating star formation. Monthly Notices of the Royal Astronomical Society 329 (3) , pp. 641-646. 10.1046/j.1365-8711.2002.05048.x

Full text not available from this repository.

Abstract

When a stellar wind bubble expands into an homogeneous medium, there are two possible outcomes. This is due to the fact that the self-gravity of the swept-up shell acts in two orthogonal directions: tangentially, to promote fragmentation of the shell, and radially, to decelerate expansion of the shell. The outcome depends on whether self-gravity works faster in the tangential or the radial direction. If the wind power ℒo is large and the effective isothermal sound speed ao in the swept-up gas is small – approximately Graphic – tangential self-gravity works faster. A thin dense shell is swept up and fragments while it is still expanding supersonically. This is the scenario often invoked to explain sequentially self-propagating star formation. However, if ℒo is small and/or ao is large, radial self-gravity works faster. Expansion of the bubble stalls before the shell can fragment. The expansion speed ceases to be supersonic, the outer shock dissipates, and the shell is neither thin nor dense. Under this circumstance, the shell is unlikely to fragment and star formation will not propagate sequentially. These conclusions are probably not altered significantly when the medium into which the wind blows is inhomogeneous, provided that the mean density on opposite sides of the bubble does not differ by many orders of magnitude.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Physics and Astronomy
Subjects: Q Science > QB Astronomy
Uncontrolled Keywords: hydrodynamics; instabilities; stars: formation; ISM: bubbles
Publisher: Oxford University Press
ISSN: 0035-8711
Last Modified: 04 Jun 2017 05:01
URI: http://orca.cf.ac.uk/id/eprint/47432

Citation Data

Cited 20 times in Google Scholar. View in Google Scholar

Cited 14 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item