The nearly circular low inclination orbits of the planets have led astronomers for centuries to consider Solar System formation within a rotating disk. Thanks to advances in detection techniques at long wavelengths sensitive to cool gas and dust, we now know that disks are a natural consequence of the star formation process. When dense cores in molecular clouds collapse, any small rotation is amplified by conservation of angular momentum, which forms an accretion disk. In addition, the star/disk system drives a powerful bipolar outflow that simultaneously removes angular momentum to allow the protostar to grow, and starts to clear away the surrounding core material. Current models invoke magnetohydrodynamic processes to tap the gravitational potential of the star/disk system to power the bipolar outflow. Once the star is optically revealed, the remnant accretion disk provides the raw material for making planets. Our knowledge of disks and outflows is increasing rapidly, in part due to observations from the Submillimeter Array that penetrate dusty environments and reveal new details of the structures within.

Submillimeter Array

Lori Allen, Sean Andrews, Tyler Bourke, Alyssa Goodman, Jes Jorgensen, Nimesh Patel, Lincoln Greenhill, Jun-Hui Zhao, , Charles Lada, Chunhua (Charlie) Qi, David Wilner, Eric E. Mamajek, Qizhou Zhang