Virial Balance in Turbulent MHD Two Dimensional Numerical Simulations of the ISM

Abstract

We present results from a virial analysis of fully nonlinear two-dimensional (2D) simulations of the ISM. We discuss the Eulerian Virial Theorem in 2D, and describe preliminary results on the virial budget of clouds in the simulations. The clouds are far from a static equilibrium, and the Virial Theorem is dominated by the time-derivative terms, indicating the importance of flux through the cloud boundaries and mass redistributions. A trend towards greater importance of the gravitational term at larger scales is observed, although a few small clouds are strongly self-gravitating. The magnetic and kinetic terms scale linearly with each other.