Structure in the Lyman-Alpha Forest
摘要
The spatial distribution of Ly-alpha forest absorption systems toward a group of 8, closely spaced QSOs has been analysed and evidence for large scale structure has been found at <z> = 2.8. Our technique is based on the first and second moments of the transmission probability density function which is capable of identifying and assessing the significance of regions of over- or underdense Ly-alpha absorption. The data has revealed at least two interesting features. 1. An overdense structure at z = 2.27 which extends at least over ~8 h^{-1} comoving Mpc (q_0 = 0.5) in the plane of the sky. Metal absorption lines have been found at the same redshift and thus a cluster or proto-cluster of galaxies seems to have been discovered. 2. A void at z = 2.97, extending over ~20 h^{-1} comoving Mpc in the plane of the sky, possibly caused by a locally increased UV ionising flux due to a foreground QSO.
引用
@article{arxiv.astro-ph/9709081,
title = {Structure in the Lyman-Alpha Forest},
author = {J. Liske and J. K. Webb},
journal= {arXiv preprint arXiv:astro-ph/9709081},
year = {2007}
}
备注
2 pages, LaTeX, with 1 PostScript figure, colour version available at ftp://edwin.phys.unsw.edu.au/pub/jol/struc_lya.fig1_col.ps.gz, uses conf_iap.sty (included). To appear in the Proceedings of the 13th IAP Colloquium (July 1-5, 1997): ``Structure and Evolution of the IGM from QSO Absorption Line Systems''