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Angular correlation function of 1.5 million luminous red galaxies: clustering evolution and a search for baryon acoustic oscillations

Sawangwit, U.; Shanks, T.; Abdalla, F.B.; Cannon, R.D.; Croom, S.M.; Edge, A.C.; Ross, N.P.; Wake, D.A.

Angular correlation function of 1.5 million luminous red galaxies: clustering evolution and a search for baryon acoustic oscillations Thumbnail


Authors

U. Sawangwit

T. Shanks

F.B. Abdalla

R.D. Cannon

S.M. Croom

A.C. Edge

N.P. Ross

D.A. Wake



Abstract

We present the angular correlation function measured from photometric samples comprising 1562 800 luminous red galaxies (LRGs). Three LRG samples were extracted from the Sloan Digital Sky Survey (SDSS) imaging data, based on colour-cut selections at redshifts, z≈ 0.35, 0.55 and 0.7 as calibrated by the spectroscopic surveys, SDSS-LRG, 2dF-SDSS LRG and QSO (quasi-stellar object) (2SLAQ) and the AAΩ-LRG survey. The galaxy samples cover ≈7600 deg2 of sky, probing a total cosmic volume of ≈5.5 h−3 Gpc3. The small- and intermediate-scale correlation functions generally show significant deviations from a single power-law fit with a well-detected break at ≈1 h−1 Mpc, consistent with the transition scale between the one- and two-halo terms in halo occupation models. For galaxy separations 1–20 h−1 Mpc and at fixed luminosity, we see virtually no evolution of the clustering with redshift and the data are consistent with a simple high peaks biasing model where the comoving LRG space density is constant with z. At fixed z, the LRG clustering amplitude increases with luminosity in accordance with the simple high peaks model, with a typical LRG dark matter halo mass 1013–1014 h−1 M⊙. For r < 1 h−1 Mpc, the evolution is slightly faster and the clustering decreases towards high redshift consistent with a virialized clustering model. However, assuming the halo occupation distribution (HOD) and Λ cold dark matter (ΛCDM) halo merger frameworks, ∼2–3 per cent/Gyr of the LRGs are required to merge in order to explain the small scales clustering evolution, consistent with previous results. At large scales, our result shows good agreement with the SDSS-LRG result of Eisenstein et al. but we find an apparent excess clustering signal beyond the baryon acoustic oscillations (BAO) scale. Angular power spectrum analyses of similar LRG samples also detect a similar apparent large-scale clustering excess but more data are required to check for this feature in independent galaxy data sets. Certainly, if the ΛCDM model were correct then we would have to conclude that this excess was caused by systematics at the level of Δw≈ 0.001–0.0015 in the photometric AAΩ-LRG sample.

Citation

Sawangwit, U., Shanks, T., Abdalla, F., Cannon, R., Croom, S., Edge, A., …Wake, D. (2011). Angular correlation function of 1.5 million luminous red galaxies: clustering evolution and a search for baryon acoustic oscillations. Monthly Notices of the Royal Astronomical Society, 416(4), 3033-3056. https://doi.org/10.1111/j.1365-2966.2011.19251.x

Journal Article Type Article
Publication Date Oct 1, 2011
Deposit Date Jan 30, 2012
Publicly Available Date Mar 28, 2024
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 416
Issue 4
Pages 3033-3056
DOI https://doi.org/10.1111/j.1365-2966.2011.19251.x
Keywords Galaxies, Elliptical and lenticular, cD, Evolution, Haloes, Cosmology, Observations, Large-scale structure of Universe.

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Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.




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