Statistical model for the initial stellar mass function
The nonlinear stages of the fragmentation of a collapsing molecular cloud are modeled by coagulation theory. Several distinct physical processes are discussed, including protostellar fragment coalescence, gas accretion, and binary formation. Our work confirms and extends the earlier result of Nakano than an approximately self-similar limiting form of the mass spectrum develops after several mean initial collision times. An approximate solution to the velocity-averaged coagulation equation is given for an arbitrary power-law dependence of the coalescence rate on mass, with dimensional dependence proportional to m/sup lambda/: the asymptotic mass spectrum varies as m/sup -3lambda/2/ at small masses and cuts off exponentially at large masses, the characteristic mass depending on the number of collision times elapsed. Simple physical arguments suggest that lambda may increase with increasing mass, but is restricted to the range 2/3< or =lambda< or =4/3. A large fraction of collisions could result in binary formation.
- Research Organization:
- Department of Astronomy, University of California, Berkeley
- OSTI ID:
- 5990882
- Journal Information:
- Astrophys. J.; (United States), Vol. 229:1
- Country of Publication:
- United States
- Language:
- English
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