EPoS Contribution
EPoS Contribution
The Protostellar Luminosity Function: Theory and Simulation

Chris McKee
UC Berkeley, Berkeley, US
The protostellar luminosity function (PLF) is a sensitive measure of how stars form, since for low-mass stars the accretion luminosity dominates the nuclear luminosity. The PLF depends on the rate at which mass accretes onto star-disk systems and thus provides a direct observational test of how molecular cores collapse; it also depends on how that mass subsequently accretes onto the protostars. Offner & McKee (2011) found that models in which stars form in approximately the same time, as in the competitive accretion or turbulent core models, were in better agreement with the data than models in which the accretion occurs at a constant rate. Hansen et al (2012) have simulated the formation of a cluster of low-mass stars including protostellar feedback in the form of both radiation and bipolar outflows, which have a significant effect on the fragmentation of, and accretion from, star-forming cores. The simulations that included both effects show that outflows reduce protostellar masses and accretion rates each by a factor of a few, resulting in an order-of-magnitude reduction in protostellar luminosities and a corresponding reduction in the effect of radiative feedback for low-mass star formation. These hydrodynamic simulations are most consistent with an accretion model that has a constant rate at low mass and approaches the turbulent core model at high mass, and they agree with observations of the PLF.
S. Offner (CFA, US)
C. Hansen (US)
R. Klein (LLNL/UCB, US)
R. Fisher (U. Mass., US)
Key publication