| Description |
Spitzer Space Telescope surveys of nearby, low-mass star-forming regions have discovered a new class of very low luminosity objects (VeLLOs), protostars embedded within dense cores with luminosities less than or equal to 0.1 Lsun. VeLLOs represent the extreme low end of the protostellar luminosity distribution, which is comprised mainly of sources below about 1 Lsun. The standard model of star formation, which predicts a mass accretion rate constant with time, is inconsistent with such a large population of low luminosity embedded protostars, leading numerous recent authors to suggest that mass accretion is variable and-or episodic in nature. Further constraints on this mass accretion process require far-IR and submm data to fill in the gap between existing Spitzer mid-IR and ground-based millimeter continuum data. We propose to obtain Herschel PACS and SPIRE 100-500 micron photometry of 24 confirmed and candidate embedded protostars with L < 1.0 Lsun. With these data, we will: (1) calculate accurate evolutionary indicators, (2) provide essential inputs for source models that seek to constrain the properties of both the protostars and the dense cores in which they are embedded, and (3) confirm or reject candidates that have not been conclusively shown to be embedded protostars. The proposed observations will provide crucial data for further understanding the protostellar luminosity distribution and mass accretion process for a very modest (6.0 hours) allocation of observing time. |
