Dongsu Ryu

Three-Dimensional MHD Simulations: the Parker Instability Under a Uniform Gravity

Using a newly developed isothermal MHD code (Kim et al. 1998a), we have performed three-dimensional, high-resolution (1283 and 2563 cells) simulations of the Parker instability under a variety of environments (e.g., under uniform or linear gravity and with or without rotation). Here, we report briefly the simulation using 2563 cells under a uniform gravity without rotation. Details as well as other simulations will be reported elsewhere (Kim et al. 1998b). An initial magnetohydrostatic equilibrium system is composed of exponentially-decreasing isothermal gas and magnetic field (along the azimuthal direction ey) under the uniform gravity (along the vertical direction ez). The size of a computational box is set to be (12H)3 where H is an e-folding scale height. 12H corresponds to the azimuthal wavelength of maximum linear growth. Random velocity perturbations are added to the initial equilibrium state.