Evidence for Large Scale Structure in the Lyman alpha Forest at z>2.6

Abstract

We present a search for spatial and redshift correlations in a 2 A resolution spectroscopic survey of the Lyman alpha forest at 2.15 < z < 3.37 toward ten QSOs concentrated within a 1-degree diameter field. We find a signal at 2.7 sigma significance for correlations of the Lyman alpha absorption line wavelengths between different lines of sight over the whole redshift range. The significance rises to 3.2 sigma if we restrict the redshift range to 2.60 < z < 3.37, and to 4.0 sigma if we further restrict the sample to lines with rest equivalent width 0.1 <= W0/(A) < 0.9. We conclude that a significant fraction of the Lyman alpha forest arises in structures whose correlation length extends at least over 30 arcmin (~26/h comoving Mpc at z=2.6 for H0 = 100h km/s/Mpc, Omega=1.0, Lambda=0). We have also calculated the three dimensional two point correlation function for Lyman alpha absorbers; we do not detect any significant signal in the data. However, we note that line blending prevents us from detecting the signal produced by a 100% overdensity of Lyman alpha absorbers in simulated data. We find that the Lyman alpha forest redshift distribution provides a more sensitive test for such clustering than the three dimensional two point correlation function.

33 pages, 11 figures, Latex, accepted for publication in ApJ, data to be published on ApJ CD-ROM, minor title correction, references updated, figures clarified

References in corpus (8)

• The Low Redshift Lyman Alpha Forest in Cold Dark Matter Cosmologies
• The Relationship Between Galaxies and Low Redshift Weak Lyman alpha Absorbers in the Directions of H1821+643 and PG1116+215
• The Gaseous Extent of Galaxies and the Origin of \lya Absorption Systems. III. Hubble Space Telescope Imaging of \lya-Absorbing Galaxies at z < 1
• Measuring the Cosmological Geometry from the Lyman Alpha Forest along Parallel Lines of Sight
• A Cluster of Low-Redshift Lyman-alpha Clouds toward PKS 2155-304. I. Limits on Metals and D/H
• A Study of Lyman-Alpha Quasar Absorbers in the Nearby Universe
• Lyman-Alpha Absorption Systems and the Nearby Galaxy Distribution
• The Bull's-Eye Effect as a Probe of $\Omega$

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