Bibcode
DOI
Tenorio-Tagle, Guillermo; Muñoz-Tuñón, Casiana; Pérez, Enrique; Silich, Sergiy; Telles, Eduardo
Referencia bibliográfica
The Astrophysical Journal, Volume 643, Issue 1, pp. 186-199.
Fecha de publicación:
5
2006
Revista
Número de citas
52
Número de citas referidas
47
Descripción
We review the structural properties of giant extragalactic H II regions
and H II galaxies based on two-dimensional hydrodynamic calculations and
propose an evolutionary sequence that accounts for their observed
detailed structure. The model assumes a massive and young stellar
cluster surrounded by a large collection of clouds. These are thus
exposed to the most important star formation feedback mechanisms:
photoionization and the cluster wind. The models show how the two
feedback mechanisms compete with each other in the disruption of clouds
and lead to two different hydrodynamic solutions: the storage of clouds
into a long-lasting ragged shell that inhibits the expansion of the
thermalized wind and the steady filtering of the shocked wind gas
through channels carved within the cloud stratum. Both solutions are
here claimed to be concurrently at work in giant H II regions and H II
galaxies, causing their detailed inner structure. This includes multiple
large-scale shells, filled with an X-ray-emitting gas, that evolve to
finally merge with each other, giving the appearance of shells within
shells. The models also show how the inner filamentary structure of the
giant superbubbles is largely enhanced with matter ablated from clouds
and how cloud ablation proceeds within the original cloud stratum. The
calculations point at the initial contrast density between the cloud and
the intercloud media as the factor that defines which of the two
feedback mechanisms becomes dominant throughout the evolution. Animated
versions of the models presented can be found at
http://www.iaa.csic.es/~eperez/ssc/ssc.html.