Protostars and Other Neutral Condensations in Hii Regions
نویسندگان
چکیده
منابع مشابه
A Radiation Driven Implosion Model for the Enhanced Luminosity of Protostars near HII Regions
Context. Molecular clouds near the H regions tend to harbor more luminous protostars. Aims. Our aim in this paper is to investigate whether or not radiation-driven implosion mechanism enhances luminosity of protostars near regions of high-ionizing fluxes. Methods. We performed numerical simulations to model collapse of cores exposed to UV radiation from O stars. We investigated dependence of...
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We review the structural properties of giant extragalactic HII regions and HII 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 ...
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We investigate the chemical abundances of NGC 3603 in the Milky Way, of 30 Doradus in the Large Magellanic Cloud, and of N66 in the Small Magellanic Cloud. Mid-infrared observations with the Infrared Spectrograph on board the Spitzer Space Telescope allow us to probe the properties of distinct physical regions within each object, the central ionizing cluster, the surrounding ionized gas, photod...
متن کاملAnomalous emission from HII regions
Spinning dust appears to be the best explanation for the anomalous emission that has been observed at ∼ 10 − 60 GHz. One of the best examples of spinning dust comes from a HII region in the Perseus molecular cloud. Observations of other HII regions also show tentative evidence for excess emission at frequencies ∼ 30 GHz, although at lower emissivity levels. A new detection of excess emission at...
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We consider the idealized expansion of an initially self-gravitating, static, singular, isothermal cloud core. For t ≥ 0, the gas is ionized and heated to a higher uniform temperature by the formation of a luminous, but massless, star in its center. The approximation that the mass and gravity of the central star is negligible for the subsequent motion of the Hii region holds for distances r
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ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 1970
ISSN: 0074-1809
DOI: 10.1017/s0074180900005039