INFALL COLLAPSE SOLUTIONS IN THE INNER LIMIT - RADIATION PRESSURE ANDITS EFFECTS ON STAR-FORMATION

this paper, we study infall collapse solutions for star formation in t he small radius limit where the particle orbits become nearly pressure free. We generalize previous solutions to simultaneously include the effects of both radiation pressure and angular momentum. The effects o f radiation pressure can be modeled using a modified potential; for re presentative cases of such potentials, we obtain analytical solutions for the density and velocity fields. In general, radiation pressure li mits the maximum mass of a forming star by reversing the infall when t he star becomes sufficiently large. Our results imply that this maximu m mass scale is given by the condition that the turnaround radius R(R) (the radius at which the radiation pressure force exceeds the gravita tional force) exceeds the centrifugal radius R(C) (the angular momentu m barrier). The maximum mass scale for a star forming within a rotatin g collapse flow with radiation pressure depends on the initial conditi ons but is generally much larger than for the case of spherical infall considered previously. In particular, stars with masses M similar to 100 M(circle dot) can form for a fairly wide range of initial conditi ons.