TEMPERATURE STRUCTURE AND METALLICITY IN H II REGIONS
نویسندگان
چکیده
منابع مشابه
Spectroscopy Of Low Metallicity Giant H II Regions: A grid of low Metallicity Stellar atmospheres
We calculate a grid of spherically symmetric OB stellar atmospheres at low metallicities, including both non-local thermodynamic equilibrium (NLTE) and metal line blanketing effects. This is done to assess the uncertainties in helium abundance determination by nebular codes due to input stellar atmosphere models. The more sophisticated stellar atmosphere models we use can differ from LTE models...
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Spatially resolved studies of star forming regions show that the assumption of spherical geometry is not realistic in most cases, with a major complication posed by the gas being ionised by multiple non-centrally located stars or star clusters. Geometrical effects including the spatial configuration of ionising sources affect the temperature and ionisation structure of these regions. We try to ...
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Theoretically, the evolution of a young stellar population depends on metallicity at least through two very important effects: the increasing opacity of the stellar material and the dependence of mass loss on metal content in high mass stars. As a consequence of the first, the effective temperature of ionizing stars should be lower in regions of higher metallicity (see for example McGaugh 1991)...
متن کاملUltracompact H Ii Regions
RESUMEN Discutimos algunos resultados observacionales recientes sobre regiones H II ultracompactas. En particular, discutimos la emisión extendida de algunas regiones H II UC y el descubrimiento de una nueva clase, denominada regiones H II " hipercompactas ". Además, describimos la obtención de la estructura de densidad usando la técnica del análisis deí ındice espectral. ABSTRACT We discuss so...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2009
ISSN: 0004-637X,1538-4357
DOI: 10.1088/0004-637x/708/2/1551