EPoS Contribution
EPoS Contribution
Identifying the Low Luminosity Population of Embedded Protostars in the c2d Observations of Clouds and Cores

Michael Dunham
University of Texas at Austin, Austin, TX, USA
The Spitzer Space Telescope Legacy Project "From Molecular Cores to Planet Forming Disks" (c2d) has completed a 3.6-160 micron imaging survey of nearby, low-mass star-forming regions. The greatly increased sensitivity of Spitzer over previous infrared surveys, such as IRAS, has led to the discovery of a new class of embedded protostars with very low luminosities. These Very Low Luminosity Objects (VeLLOs) pose a challenge to our understanding of low-mass star formation as their luminosities are well below that expected for accretion onto protostars with masses greater than brown dwarfs. They must feature either mass accretion rates far lower than predicted by the standard model of star formation, masses far below the stellar/sub-stellar boundary, or some combination of the two. We have recently completed a study to identify the complete population of embedded protostars with luminosities less than 1 solar luminosity in the c2d dataset. With this sample we address several outstanding questions: How many dense cores previously classified as starless in fact harbor low-luminosity embedded protostars? What is the shape of the low end of the distribution of embedded protostellar luminosities? What are the implications of the properties of this sample on the mass accretion processes in low-mass star formation?