SOFIA Observations of Intermediate Luminosity Protostars in Orion and their Outflows

Observations of protostars probe the transition of interstellar matter into stars and shape our understanding of how infall, accretion and outflow determine the masses of stars, the properties of nascent planetary systems, and the rate and efficiency of star formation. While the protostellar luminosity function peaks around 1 solar luminosity, 10% of protostars have luminosities from 20-1000 solar luminosities. These intermediate luminosity protostars include precursors of intermediate mass stars as well lower mass protostars undergoing large accretion driven outbursts. Their study is important for understanding the origin of the IMF, the role of episodic accretion in low mass star formation, and the impact of feedback from protostars on the surrounding cloud. We present SOFIA observations made with FORCAST and GREAT of five intermediate mass protostars. These were identified in the Herschel Orion Protostar Survey (HOPS) using 2-870 micron SEDs from 2MASS, Spitzer, Hershel and APEX photometry. SOFIA/FORCAST 9-14 micron spectra are combined with the HOPS photometry of these sources to refine our measurements of their luminosities and envelope properties. SOFIA/GREAT observations trace the outflow from the most luminous of the protostars, HOPS 370 or OMC2 FIR3, in far-IR lines of CO and [OI]. By combining the line profiles from GREAT with line maps from PACS/Herschel, we find both far-IR emission from the jet launched by the protostar and from the gas swept up by the jet. By comparing the far-IR maps and line profiles with ground-based sub-mm data from the APEX telescope and centimeter wave continuum from the VLA, we build a detailed portrait of the mass flow in the outflow and its impact on the surrounding dense gas.