HI Absorption in GPS/CSS Sources
Abstract
Combining our own observations with data from the literature, we consider the incidence of HI absorption in Gigahertz Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) sources. Here we present our preliminary results, where we find that the smaller GPS sources (<1 kpc) on average have larger HI column densities than the larger CSS sources (>1 kpc). Both a spherical and an axi-symmetric gas distribution, with a radial power law density profile, can be used to explain this anti-correlation between projected linear size and HI column density. Since most detections occur in galaxy classified objects, we argue that if the unified schemes apply to the GPS/CSSs, a disk distribution for the HI is more likely.
Cite
@article{arxiv.astro-ph/0212418,
title = {HI Absorption in GPS/CSS Sources},
author = {Y. M. Pihlstroem and J. E. Conway and R. C. Vermeulen},
journal= {arXiv preprint arXiv:astro-ph/0212418},
year = {2009}
}
Comments
6 pages, 3 figures, LaTeX. Accepted by Publications of the Astronomical Society of Australia, as a contribution to The 3rd GPS/CSS Workshop, ed. T. Tzioumis, W. de Vries, I. Snellen, A. Koekemoer