Non-Voigt Lyman-alpha absorption line profiles
Abstract
Recent numerical simulations have lead to a paradigm shift in our understanding of the intergalactic medium, and the loss of a physical justification for Voigt profile fitting of the Lyman-alpha forest. Many individual lines seen in simulated spectra have significant departures from the Voigt profile, yet could be well fitted by a blend of two or more such lines. We discuss the expected effect on the line profiles due to ongoing gravitational structure formation and Hubble expansion. We develop a method to detect departures from Voigt profiles of the absorption lines in a statistical way and apply this method to simulated Lyman-alpha forest spectra, confirming that the profiles seen do statistically differ from Voigt profiles.
Cite
@article{arxiv.astro-ph/9912091,
title = {Non-Voigt Lyman-alpha absorption line profiles},
author = {P. J. Outram and R. F. Carswell and T. Theuns},
journal= {arXiv preprint arXiv:astro-ph/9912091},
year = {2009}
}
Comments
Accepted for publication in ApJL. 10 pages, 3 figures