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Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2018

University of Nevada, Las Vegas

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Full-Text Articles in Physical Sciences and Mathematics

Diffusion And Concentration Of Solids In The Dead Zone Of A Protoplanetary Disk, Chao-Chin Yang, Mordecai-Mark Mac Low, Anders Johansen Nov 2018

Diffusion And Concentration Of Solids In The Dead Zone Of A Protoplanetary Disk, Chao-Chin Yang, Mordecai-Mark Mac Low, Anders Johansen

Physics & Astronomy Faculty Research

The streaming instability is a promising mechanism to drive the formation of planetesimals in protoplanetary disks. To trigger this process, it has been argued that sedimentation of solids onto the mid-plane needs to be efficient, and therefore that a quiescent gaseous environment is required. It is often suggested that dead-zone or disk-wind structure created by non-ideal magnetohydrodynamical (MHD) effects meets this requirement. However, simulations have shown that the mid-plane of a dead zone is not completely quiescent. In order to examine the concentration of solids in such an environment, we use the local-shearing-box approximation to simulate a particlegas system with …


Streaming Instability Of Multiple Particle Species In Protoplanetary Disks, Noemi Schaffer, Chao-Chin Yang, Anders Johansen Oct 2018

Streaming Instability Of Multiple Particle Species In Protoplanetary Disks, Noemi Schaffer, Chao-Chin Yang, Anders Johansen

Physics & Astronomy Faculty Research

The radial drift and diffusion of dust particles in protoplanetary disks affect both the opacity and temperature of such disks, as well as the location and timing of planetesimal formation. In this paper, we present results of numerical simulations of particle-gas dynamics in protoplanetary disks that include dust grains with various size distributions. We have considered three scenarios in terms of particle size ranges, one where the Stokes number τs = 10−1−100, one where τs = 10−4−10−1, and finally one where τs= 10−3−100. Moreover, we considered both discrete and continuous distributions in particle size. In accordance with previous works we …


Rossby Vortices In Thin Magnetized Accretion Discs, L. Matilsky, Sergei Dyda, R. V. E. Lovelace, P. S. Lii Aug 2018

Rossby Vortices In Thin Magnetized Accretion Discs, L. Matilsky, Sergei Dyda, R. V. E. Lovelace, P. S. Lii

Physics & Astronomy Faculty Research

We study the Rossby wave instability (RWI) in a thin accretion disc threaded by an initially toroidal magnetic field using the magnetohydrodynamics (MHD) code PLUTO... See full text for full abstract.