NEW ANALYTIC AND QUASI-ANALYTIC SOLUTIONS FOR WIND-DRIVEN COMPACT HII REGIONS
Ultracompact HII regions are in a regime of approximate pressure balance with the surrounding, dense molecular clouds. In this paper, we apply a newly developed "thick shell" formalism to the case of an expanding HII region ener- gized by both the photoionizing radiation and the wind from...
| Autores: | , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2012 |
| País: | México |
| Recursos: | Universidad Nacional Autónoma de México |
| Repositorio: | Redalyc-UNAM |
| OAI Identifier: | oai:redalyc.org:57124423004 |
| Acesso em linha: | https://www.redalyc.org/articulo.oa?id=57124423004 |
| Access Level: | acceso abierto |
| Palavra-chave: | Física, Astronomía y Matemáticas HII regions ISM: evolution stars: formation ISM: kinematics and dynamics |
| Resumo: | Ultracompact HII regions are in a regime of approximate pressure balance with the surrounding, dense molecular clouds. In this paper, we apply a newly developed "thick shell" formalism to the case of an expanding HII region ener- gized by both the photoionizing radiation and the wind from the central stellar source. The resulting model leads to analytic and quasi-analytic solutions that have a transition to a regime (absent in the classical "wind-driven bubble" analytic solutions) in which the hot, stellar wind bubble expands quasi-statically, in ap- proximate pressure equilibrium with the surrounding ISM. This regime is relevant for the observed ultracompact HII regions. We present the time-evolution of the radius and the thickness of the expanding HII shell for different values of a single, dimensionless parameter that determines the characteristics of the solution. |
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