Título del libro: Reviews In Modern Astronomy 16: The Cosmic Circuit Of Matter
Título del capítulo: The Interstellar Medium and Star Formation: The Impact of Massive Stars
STANLEY EUGENE KURTZ SMITH; GUILLERMO MIGUEL GARCIA SEGURA;
Autores externos:
Idioma:
Inglés
Año de publicación:
2008
Resumen:
We discuss the interaction of massive stars with their parental molecular clouds. A summary of recent observational developments is presented, followed by a synopsis of the dynamical evolution of H II regions and wind-driven bubbles in high-pressure cloud cores. Both ultracompact H II regions and ultracompact wind-driven bubbles can reach pressure equilibrium with their surrounding medium. The structures stall their expansion and become static and, as long as the ionization sources and the ambient densities remain about constant, the resulting regions are stable and long lived. For cases with negative density gradients, and depending on the density distribution, some regions never reach the static equilibrium condition. For power-law density stratifications, ? ? r-w, the properties of the evolution depend on a critical exponent, wcrit, above which the ionization front cannot be slowed down by recombinations or new ionizations, and the cloud becomes fully ionized. This critical exponent is wcrit = 3/2 during the expansion phase. We discuss three regimes, w < 3/2, 3/2 < w < 3, and w > 3. We summarize numerical modeling that shows how the movement of the exciting star through a non-uniform medium can give rise to hyper and ultracompact H II regions, with the presence of extended emission. © 2003 WILEY-VCH GrnbH & Co. KGaA, Weinheirn. All rights reserved.
Entidades citadas de la UNAM:
ISBN:
9783527617647
Editorial:
wiley Nombre de la publicación:
The Interstellar Medium and Star Formation: The Impact of Massive Stars
Página inicial:
85
Página final:
113
