Astronomy and Astrophysics – Astrophysics
Scientific paper
Aug 1982
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1982a%26a...112..104t&link_type=abstract
Astronomy and Astrophysics, vol. 112, no. 1, Aug. 1982, p. 104-110. Research supported by the Thyssen Stiftung.
Astronomy and Astrophysics
Astrophysics
28
B Stars, Gas Dynamics, O Stars, Stellar Envelopes, Stellar Evolution, H Ii Regions, Ionizing Radiation, Nebulae, Star Clusters, Stellar Winds
Scientific paper
One- and two-dimensional calculations of the gasdynamical evolution of H II regions excited by an evolving OB association are presented. The various phases (classical expansion, recombination, reionization and full recombination, phases I-IV, respectively) are studied and found to depend not only on the behaviour of the stellar photon flux, but also on the initial value of the ambient density. Phase II, (recombination) leads to the formation of a large expanding thick neutral shell. However, for large values of the ambient density, phase II can be inhibited and the H II region will continue to expand according to the classical formulation, even though the ionizing photon flux from the source continues to decay. The latter evolution will make the H II region appear as a ring-like nebula for a considerable period of time. Many of the galactic and extragalactic ring-like nebulae and expanding neutral shells, usually interpreted as the result of supernova explosions or stellar winds, can thus be explained with the present calculations.
Beltrametti M.
Bodenheimer Peter
Tenorio-Tagle Guillermo
Yorke Harold W.
No associations
LandOfFree
The gas dynamics around OB association. II - Dependence on the initial ambient density does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The gas dynamics around OB association. II - Dependence on the initial ambient density, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The gas dynamics around OB association. II - Dependence on the initial ambient density will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-899180