Protostars and Planets VI, Heidelberg, July 15-20, 2013

Poster 2S054

Turbulence in Protoplanetary Disks

Simon, Jacob (JILA, University of Colorado)
Bai, Xue-Ning (ITC, Harvard Cfa)
Armitage, Philip (JILA, University of Colorado)
Stone, James (Princeton University)
Beckwith, Kris (Tech-X Corporation)

We study the nature of magnetohydrodynamic (MHD) turbulence in protoplanetary disks driven by the magnetorotational instability (MRI) in order to understand the conditions under which planets first begin to form. In particular, we present a series of high resolution gas dynamics simulations that are focused on several radial regions in a model protoplanetary disk. Close to the star where the gas is fully ionized, strong features called \"zonal flows\" appear in the gas pressure; these features could potentially trap small dust particles for long periods of time, playing a significant role in early planet formation processes. At large disk radii where the gas density is lower, ambipolar diffusion dominates and creates regions where the MRI is less efficient at generating turbulence. However, zonal flows may persist in these “ambipolar damping zones” as well, making them potential sites for planet formation in the outer disk. Finally, we show that at these large distances, the geometry and strength of the magnetic field play an important role in setting the level of turbulence throughout the disk’s vertical extent and thus the accretion rate onto the central protostar.

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