Atomic and Molecular Absorption at High Redshift
Abstract
Strong constraints on possible variations in fundamental constants can be derived from HI 21-cm and molecular rotational absorption lines observed towards quasars. With the aim of forming a statistical sample of constraints we have begun a program of systematic searches for such absorption systems. Here we describe molecular rotational searches in 25 damped Lyman-alpha systems where, in many cases, we set optical depth limits an order of magnitude better than that required to detect the 4 known redshifted millimeter-wave absorbers. We also discuss the contributory factors in the detectability of HI 21-cm absorption, focusing on possible biases (e.g.low covering factors) in the currently known sample of absorbers and non-detections.
Cite
@article{arxiv.astro-ph/0310672,
title = {Atomic and Molecular Absorption at High Redshift},
author = {S. J. Curran and J. K. Webb and M. T. Murphy and Y. M. Pihlström},
journal= {arXiv preprint arXiv:astro-ph/0310672},
year = {2016}
}
Comments
4 pages, to appear in The Neutral ISM in Starburst Galaxies, ASP Conference Series, 2003, edited by S. Aalto, S. Huettemeister, A. Pedlar