Open AccessCollapse of low‐mass clouds in the presence of a UV radiation field
Author(s) -
Susa Hajime,
Kitayama Tetsu
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03616.x
Subject(s) - physics , astrophysics , isothermal process , radiation , thermal radiation , thermal , field (mathematics) , core (optical fiber) , gravitational collapse , thermodynamics , optics , mathematics , pure mathematics
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 H 2 cooling dominates photoheating and the temperature drops to below 10 4 K. Consequently, the mass of the cooled core is evaluated as M cool =3.6×10 6 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.