Scale-free Equilibria of Magnetized Polytropic Clouds
Abstract
We investigate the equilibrium properties of self-gravitating magnetized clouds with polytropic equations of state with negative index n. In particular, we consider scale-free isopedic configurations that have constant dimensionless spherical mass-to-flux ratio lambda_r and that may constitute ``pivotal'' states for subsequent dynamical collapse to form groups or clusters of stars. For given Gamma = 1 + 1/n, equilibria with smaller values of lambda_r are more flattened, ranging from spherical configurations with lambda_r = infinity to completely flattened states for lambda_r=1. For a given amount of support provided by the magnetic field as measured by the dimensionless parameter H_0, equilibria with smaller values of Gamma are more flattened. However, logatropic (defined by Gamma = 0) disks do not exist. The only possible scale-free isopedic equilibria with logatropic equation of state are spherical uniformly magnetized clouds.
Cite
@article{arxiv.astro-ph/9904028,
title = {Scale-free Equilibria of Magnetized Polytropic Clouds},
author = {D. Galli and S. Lizano and Z. -Y. Li and F. C. Adams and F. H. Shu},
journal= {arXiv preprint arXiv:astro-ph/9904028},
year = {2009}
}
Comments
31 pages, 7 figures. The Astrophysical Journal, in press