Augusto Carballido
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Augusto Carballido has a total of 2 co-authors. Here are the top co-authors by number of shared publications:
- James E. Pringle
Institute of Astronomy University of Cambridge CB3 0HA Cambridge UK
2 shared publications - James M. Stone
Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA
2 shared publications
Latest Publications
- Open Access
- 11 April 2005
- Published by Oxford University Press (OUP) in Monthly Notices of the Royal Astronomical Society
- Vol. 358 (3) , 1055-1060
Diffusion coefficient of a passive contaminant in a local MHD model of a turbulent accretion disc
- 11 April 2005
- Published by Oxford University Press (OUP) in Monthly Notices of the Royal Astronomical Society
- Vol. 358 (3) , 1055-1060
Open AccessDiffusion coefficient of a passive contaminant in a local MHD model of a turbulent accretion disc
- Open Access
Diffusion coefficient of a passive contaminant in a local MHD model of a turbulent accretion disc
We calculate the radial diffusion coefficient for a passive contaminant in an accretion disc which is turbulent due to the action of the magnetorotational instability. Numerical MHD simulations are used to follow the evolution of a local patch of the disc using the shearing box formalism. A separate continuity equation for the mass fraction of contaminant is integrated along with the MHD system, and radial profiles of this fraction are obtained as a function of time. Solutions of a linear diffusion equation are fitted to the numerical measured profiles of the contaminant, treating the diffusion coefficient D as the fitting parameter. At early times, the value of D is found to vary, however once the contaminant is spread over scales comparable to the box size, it saturates at a steady value. The ratio of D to the transport coefficient of angular momentum due to shear stress is small. If D can be used as a proxy for the turbulent magnetic diffusivity, the effective magnetic Prandtl number P_eff=\nu/D (where \nu is the coefficient of "efective viscosity" associated with shear stress) would be large.
Open AccessDiffusion coefficient of a passive contaminant in a local MHD model of a turbulent accretion disc
We calculate the radial diffusion coefficient for a passive contaminant in an accretion disc which is turbulent due to the action of the magnetorotational instability. Numerical MHD simulations are used to follow the evolution of a local patch of the disc using the shearing box formalism. A separate continuity equation for the mass fraction of contaminant is integrated along with the MHD system, and radial profiles of this fraction are obtained as a function of time. Solutions of a linear diffusion equation are fitted to the numerical measured profiles of the contaminant, treating the diffusion coefficient D as the fitting parameter. At early times, the value of D is found to vary, however once the contaminant is spread over scales comparable to the box size, it saturates at a steady value. The ratio of D to the transport coefficient of angular momentum due to shear stress is small. If D can be used as a proxy for the turbulent magnetic diffusivity, the effective magnetic Prandtl number P_eff=\nu/D (where \nu is the coefficient of "efective viscosity" associated with shear stress) would be large.