Dynamical HII Region Evolution in Turbulent Molecular Clouds
Abstract
We present numerical radiation-hydrodynamic simulations of the evolution of HII regions formed in an inhomogeneous medium resulting from turbulence simulations. We find that the filamentary structure of the underlying density distribution produces a highly irregular shape for the ionized region, in which the ionization front escapes to large distances in some directions within 80,000 years. In other directions, on the other hand, neutral gas in the form of dense globules persists within 1 parsec of the central star for the full duration of our simulation (400,000 years). Divergent photoablation flows from these globules maintain a root-mean-squared velocity in the ionized gas that is close to the ionized sound speed. Simulated images in optical emission lines show morphologies that are in strikingly detailed agreement with those observed in real HII regions.
Cite
@article{arxiv.astro-ph/0512554,
title = {Dynamical HII Region Evolution in Turbulent Molecular Clouds},
author = {Garrelt Mellema and S. Jane Arthur and William J. Henney and Ilian T. Iliev and Paul R. Shapiro},
journal= {arXiv preprint arXiv:astro-ph/0512554},
year = {2008}
}
Comments
Minor changes to sync with accepted version. 7 pages, ApJ in press. Accompanying video available at http://ifront.org/wiki/Turbulent_Hii_Regions/Papers