Probing the intergalactic medium-galaxy connection toward PKS 0405-123. II. A cross-correlation study of Lyα absorbers and galaxies at z < 0.5

Hsiao Wen Chen, Jason X. Prochaska, Benjamin J. Weiner, John S. Mulchaey, Gerard M. Williger

Research output: Contribution to journalArticlepeer-review

50 Scopus citations

Abstract

We present a pilot study of the clustering properties of Lyα absorbers with respect to known galaxies based on 112 Lyα absorbers and 482 galaxies identified at z < 0.5 along the sight line toward PKS 0405-123. The principal goal is to determine the origin of Lyα absorbers based on their cross-correlation amplitude with known galaxies and to investigate a possible N(H I) dependence of the cross-correlation function. The main results of our study are as follows: (1) The cross-correlation function ξ ga measured using only emission-line-dominated galaxies and Lyα absorbers with log N(H I) ≥ 14 shows a comparable strength to the galaxy autocorrelation function ξgg on comoving, projected distance scales of less than 1 h-1 Mpc, while there remains a lack of cross-correlation signal when using only absorption-line-dominated galaxies. This signifies a morphology-dependent ξga and indicates that strong absorbers with log N(H I) ≥ 14 and emission-line galaxies reside in the same halo population. (2) A maximum likelihood analysis shows that Lyα absorbers with log N(H I) < 13.6 are consistent with being more randomly distributed with respect to known galaxies. (3) Finally, we find based on this single sight line that the amplitude of ξga does not depend sensitively on N(H I) for strong absorbers, with log N(H I) ≥ 13.6.

Original languageEnglish (US)
Pages (from-to)L25-L28
JournalAstrophysical Journal
Volume629
Issue number1 II
DOIs
StatePublished - Aug 10 2005
Externally publishedYes

Keywords

  • Galaxies: evolution
  • Quasars: absorption lines

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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