SF-04-0008

Dust In the wind: A search for dust in the outflow of the HH212 class 0 protostellar system

Adele Plunkett, Hannah Shoemaker, Jon Ramsey, Per Bjerkeli

Star formation is a physically complex process that begins with the gravitational collapse of dense clouds of dust and gas, and that culminates in the formation of a protostar and accompanying protoplanetary disk. It is in this disk that planets eventually form through the collisional growth of smaller dust grains into larger ones, and eventual gravitational collapse into planetesimals. Perhaps the most visually striking phenomenon during star formation is the ejection of material along the direction of the protostar's rotational axis. These ejections are observed in the form of molecular outflows and/or atomic jets, and carry away mass, energy and angular momentum from the system. Given the known dust content of protoplanetary disks, and the energetics of outflows, it has been suggested that it should be possible to lift dust from disks via winds, but this has yet to be directly confirmed observationally. A detection of dust within protostellar outflows would not only put constraints on the dust content in outflows, but if a sufficient amount of dust can be removed, the mass budget for planet formation could also be affected. We present re-imaging of archival, multi-frequency dust continuum observations taken with the Atacama Large Millimeter/sub-millimeter Array (ALMA) towards the HH212 protostellar system. We detect an extension in the dust emission coincident with the molecular outflow, and using multi-frequency data in Bands 7 and 9, we estimate the spectral index of the emitting dust and the dust mass in the wind launching region. We find a small but still significant amount of dust mass coincident with the molecular outflow cavity, and we take this as evidence that the wind is indeed carrying away dust from the HH212 protoplanetary disk.