UV radiation fields in dark clouds
نویسندگان
چکیده
منابع مشابه
Magnetic Fields in High-mass Infrared Dark Clouds
High-mass Stars are cosmic engines known to dominate the energetics in the Milky Way and other galaxies. However, their formation is still not well understood. Massive, cold, dense clouds, often appearing as Infrared Dark Clouds (IRDCs), are the nurseries of massive stars. No measurements of magnetic fields in IRDCs in a state prior to the onset of high-mass star formation (HMSF) have previousl...
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We study alignment of grains by radiative torques. We found a steep rise in radiative torque efficiency as grain size increases. This allows the larger grains that are known to exist within molecular clouds to be aligned by the attenuated and reddened interstellar radiation field. In particular, we found that, even deep inside giant molecular clouds, e.g., at optical depths corresponding to AV ...
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Scattering of solar radiation by clouds can reduce or enhance solar global irradiance compared to cloudless-sky irradiance at the Earth’s surface. Cloud effects to global irradiance can be described by Cloud Modification Factors (CMF). Depending on strength and duration, irradiance enhancements affect the energy balance of the surface and gain of solar power for electric energy generation. In t...
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The collapse of marginally Jeans unstable primordial gas clouds in the presence of UV radiation field is discussed. Assuming that the dynamical collapse proceeds approximately in an isothermal self-similar fashion, we investigate the thermal evolution of collapsing central core until H2 cooling dominates photoheating and the temperature drops to below 10K. Consequently, the mass of the cooled c...
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ژورنال
عنوان ژورنال: Astrophysics and Space Science
سال: 1975
ISSN: 0004-640X,1572-946X
DOI: 10.1007/bf00646756