Collapse of low-mass clouds in the presence of a UV radiation field |
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| Authors: | Hajime Susa Tetsu Kitayama |
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| Institution: | Center for Computational Physics, University of Tsukuba, Tsukuba 305, Japan;Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo, Japan |
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| Abstract: | The collapse of marginally Jeans-unstable primordial gas clouds in the presence of a UV radiation field is discussed. Assuming that the dynamical collapse proceeds approximately in an isothermal self-similar fashion, we investigate the thermal evolution of the collapsing central core until H2 cooling dominates photoheating and the temperature drops to below 104 K. Consequently, the mass of the cooled core is evaluated as M cool=3.6×106 M⊙ ( I 21/1)?0.32. This scale depends only on the incident UV intensity, and provides a lower limit to the mass of collapsed objects in the UV radiation field. |
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| Keywords: | molecular processes radiative transfer galaxies: formation |
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