RG Research: Disks and Outflows

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.

Project Links

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

  disk around the nearby young star HD 163296

The disk around the nearby young star HD 163296 observed with the Submillimeter Array. The position of the central star is indicated by the star symbol. The contours show CO line intensity, which traces an inclined disk of cool molecular gas, and the color scale represents the line-of-sight velocity of the gas, from blue (approaching) to red (receding), in a beautifully symmetric pattern of Keplerian motion. Image Source: Ph.D. thesis of Andrea Isella (Milan/Arcetri).


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