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| Paper: |
Evolutionary Models of the Formation of Protostars out of Low-Mass, Dense Cores: Towards Reconciling Models and Observations |
| Volume: |
432, New Horizons in Astronomy: Frank N. Bash Symposium 2009 |
| Page: |
197 |
| Authors: |
Dunham, M. M.; Evans II, N. J.; Terebey, S.; Dullemond, C. P.; Young, C. H. |
| Abstract: |
A long-standing problem in low-mass star formation is the “luminosity problem,” whereby protostars are underluminous compared to the expected accretion luminosity. Motivated by this problem, we present a set of evolutionary models describing the collapse of low-mass, dense cores into protostars, using the evolutionary models
describing the collapse of low-mass, dense cores into protostars, using
the Young & Evans (2005) evolutionary models as our starting point.
We calculate the radiative transfer, spectral energy distributions, and observational signatures of the collapsing cores to directly compare to observations. We incorporate several additions to the Young & Evans (2005) model in an effort to better match observations, including: (1) the opacity from scattering, (2) a circumstellar disk directly in the 2-D radiative transfer, (3) a two-dimensional, rotationally flattened envelope, (4) mass-loss and the opening of outflow cavities, and (5) a simple treatment of episodic mass accretion. We find that scattering, two-dimensional geometry, mass-loss, and outflow cavities all affect the model predictions, as expected, but none resolve the luminosity problem. On the other hand, a cycle of episodic mass accretion similar to that predicted by recent theoretical work can resolve this problem and bring the model predictions into better agreement with observations. |
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