Invited Presentation
MASSES: Probing the Origins of Protostars
Presenter: Philip Myers (Center for Astrophysics | Harvard & Smithsonian)
In the MASSES project, the SMA surveyed a complete sample of 74 protostars and their environments in the Perseus complex. Observations were made in the 850 µm and 1.3 mm continuum and in numerous lines tracing outflows and protostellar envelopes, on scales extending from ~300 au. MASSES is the largest molecular line survey of protostellar regions in a single star-forming complex at these scales. This talk focuses on three recent results: (1) well-defined outflows become wider as the protostellar spectral energy distribution becomes bluer, as expected in evolutionary models. (2) outflow directions are set locally, since they are uncorrelated with the direction of their nearest host filament, and are uncorrelated with the directions of neighboring outflows in multiple systems. (3) the number of compact structures in regions of increasing density in Perseus can be described by "inefficient thermal Jeans fragmentation" over scales from 20 pc down to ~20 au. This "thermal" description fits the data better than a "turbulent" one based on supersonic line widths.
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