Star Formation in Giant Extragalactic H II Regions
نویسندگان
چکیده
منابع مشابه
A Comprehensive Study of High-metallicity Giant Extragalactic H Ii Regions: Ionizing Populations
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 کاملMeasuring Chemical Abundances in Extragalactic Metal-Rich H II Regions
The analysis of metal-rich H ii regions has a profound impact on the calibration of abundance diagnostics widely used to measure the chemical content of star-forming galaxies, both locally and at high redshift. I review the main difficulties that affect direct abundance determinations from temperature-sensitive collisionally excited lines, and briefly discuss strong-line methods, in particular ...
متن کاملMSX Mid infra red imaging of massive star birth environments . II : Giant H II regions
We present mid-IR (MIR) 21μm images of a complete set of 40 radio selected Galactic giant H II regions from Smith et al., (1978) obtained with the Mid-course Space Experiment (MSX). This wavelength is sampling thermal emission from the ubiquitous dust present within the exciting clusters of OB stars. The spatial morphology often indicates multiple emission sources, suggesting complicated cluste...
متن کاملMid infra red imaging of massive star birth environments . II : Giant H II regions
We conduct a Galactic census of Giant H II regions, based on the all sky 6cm dataset of Kuchar & Clark, plus the kinematic distances obtained by Russeil. From an inspection of mid-IR Mid-course Space Experiment (MSX) and far-IR IRAS Sky Survey Atlas images we identify a total of 56 GH II regions in the Milky Way, of which 15% (65%) can be seen at optical (near-IR) wavelengths. The mid to far-IR...
متن کاملRadial brightness profiles of extragalactic H II regions
We present a systematic study of the radial brightness profiles in Hα of a set of H ii regions in 6 late-type spiral galaxies, complete down to stated limiting luminosities. We have sufficient linear resolution in our observations to be able to fit models in which the effects of the radial fall off in density and in mean degree of ionization can be distinguished. We find a sharp break in the pl...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Publications of the Astronomical Society of the Pacific
سال: 1994
ISSN: 0004-6280,1538-3873
DOI: 10.1086/133396