Density Distribution of the Warm Ionized Medium
Abstract
Observations of Halpha emission measures and pulsar dispersion measures at high Galactic latitude (|b| > 10 deg) provide information about the density and distribution of the diffuse warm ionized medium (WIM). The diffuse WIM has a lognormal distribution of EM sin |b|, which is consistent with a density structure established by isothermal turbulence. The H+ responsible for most of the emission along high-EM sin |b| sightlines is clumped in high density (> 0.1 cm^{-3}) regions that occupy only a few parsecs along the line of sight, while the H+ along low-EM sightlines occupies hundreds of parsecs with considerably lower densities.
Cite
@article{arxiv.astro-ph/0701477,
title = {Density Distribution of the Warm Ionized Medium},
author = {Alex S. Hill and Ronald J. Reynolds and Robert A. Benjamin and L. Matthew Haffner},
journal= {arXiv preprint arXiv:astro-ph/0701477},
year = {2007}
}
Comments
To appear in the proceedings of the "SINS - Small Ionized and Neutral Structures in the Diffuse Interstellar Medium" conference, eds. M. Haverkorn and W.M. Goss