The flux auto- and cross-correlation of the Lyα forest. I. Spectroscopy of QSO pairs with arcminute separations and similar redshifts

Andrew R. Marble, Kristoefer A. Eriksen, Chris D. Impey, Bai Lei, Lance Miller

Research output: Contribution to journalArticle

7 Scopus citations


The Lyα forest has opened a new redshift regime for cosmological investigation. At z > 2 it provides a unique probe of cosmic geometry and an independent constraint on dark energy that is not subject to standard candle or ruler assumptions. In Paper I of this series on using the Lya forest observed in pairs of QSOs for a new application of the Alcock-Paczynski test, we present and discuss the results of a campaign to obtain moderate-resolution spectroscopy (FWHM ≃ 2.5 Å) of the Lyα forest in pairs of QSOs with small redshift differences (Δz < 0.25, z > 2.2) and arc-minute separations (θ < 5′). This data set, composed of seven individual QSOs, 35 pairs, and one triplet, is also well suited for future investigations of the coherence of Lya absorbers on ∼1 Mpc transverse scales and the transverse proximity effect. We note seven revisions for previously published QSO identifications and/or redshifts.

Original languageEnglish (US)
Pages (from-to)29-47
Number of pages19
JournalAstrophysical Journal, Supplement Series
Issue number1
StatePublished - Mar 1 2008



  • Cosmology: observations
  • Errata, addenda
  • Intergalactic medium
  • Quasars: absorption lines

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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