RESOLVING THE LUMINOSITY PROBLEM IN LOW-MASS STAR FORMATION

By M. Dunham, Eduard I. Vorobyov. 2011

136 citations recorded by the source corpus.

We determine the observational signatures of protostellar cores by coupling two-dimensional radiative transfer calculations with numerical hydrodynamical simulations that predict accretion rates that both decline with time and feature short-term variability and episodic bursts caused by disk gravitational instability and fragmentation. We calculate the radiative transfer of the collapsing cores throughout the full duration of the collapse, using as inputs the core, disk, protostellar masses, radii, and mass accretion rates predicted by the hydrodynamical simulations. From the resulting spectral energy distributions, we calculate standard observational signatures (Lbol, Tbol, Lbol/Lsmm) to directly compare to observations. We show that the accretion process predicted by these models reproduces the full spread of observed protostars in both Lbol–Tbol and Lbol–Mcore space, including very low luminosity objects, provides a reasonable match to the observed protostellar luminosity distribution, and resolves the long-standing luminosity problem. These models predict an embedded phase duration shorter than recent observationally determined estimates (0.12 Myr versus 0.44 Myr), and a fraction of total time spent in Stage 0 of 23%, consistent with the range of values determined by observations. On average, the models spend 1.3% of their total time in accretion bursts, during which 5.3% of the final stellar mass accretes, with maximum values being 11.8% and 35.5% for the total time and accreted stellar mass, respectively. Time-averaged models that filter out the accretion variability and bursts do not provide as good of a match to the observed luminosity problem, suggesting that the bursts are required.

Subfields: Astronomy and Astrophysics, Atmospheric Science, Spectroscopy

View Paper: https://www.semanticscholar.org/paper/638703f77d5a6f69deea45f6b06782549e704fff

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. L. Hartmann
2. N. Calvet
3. L. Allen
4. K. Luhman
5. Eduard I. Vorobyov
6. S. Megeath
7. S. Basu
8. E. Furlan

In Atmospheric Science

1. L. Hartmann
2. L. Allen
3. S. Basu
4. Eduard I. Vorobyov

In Spectroscopy

1. N. Calvet
2. Eduard I. Vorobyov
3. L. Allen
4. L. Hartmann
5. S. Basu
6. S. Megeath
7. K. Luhman
8. P. Myers

Citations in the corpus

• THE HERSCHEL ORION PROTOSTAR SURVEY: SPECTRAL ENERGY DISTRIBUTIONS AND FITS USING A GRID OF PROTOSTELLAR MODELS (2016, background): “Also the accretion history, which likely includes episodic accretion events and thus temporary increases in luminosity, adds to this uncertainty (Dunham et al. 2010; Dunham & Vorobyov 2012).”
• VARIABLE PROTOSTELLAR ACCRETION WITH EPISODIC BURSTS (2015, background): “Accretion rates gradually declining in time and showing episodic bursts were shown to resolve this ”luminosity problem” (Dunham & Vorobyov 2012).”