The 2dF-SDSS LRG and QSO Survey: the LRG 2-point correlation function and redshift-space distortions

By N. Ross, J. daÂngela, T. Shanks, D. Wake, R. Cannon, A. Edge, R. Nichol, P. Outram, M. Colless, W. Couch and 10 more. 2006

178 citations recorded by the source corpus.

We present a clustering analysis of luminous red galaxies (LRGs) using nearly 9000 objects from the final, three-year catalogue of the 2dF-SDSS LRG and QSO (2SLAQ) Survey. We measure the redshift-space two-point correlation function, ξ(s) and find that, at the mean LRG redshift of shows the characteristic downturn at small scales (1 h−1 Mpc) expected from line-of-sight velocity dispersion. We fit a double power law to ξ(s) and measure an amplitude and slope of s0 = 17.3+2.5−2.0 h−1 Mpc, γ = 1.03 ± 0.07 at small scales (s 4.5 h−1 Mpc). In the semiprojected correlation function, wp(σ), we find a simple power law with γ = 1.83 ± 0.05 and r0 = 7.30 ± 0.34 h−1 Mpc fits the data in the range 0.4 < σ < 50 h−1 Mpc, although there is evidence of a steeper power law at smaller scales. A single power law also fits the deprojected correlation function ξ(r), with a correlation length of r0 = 7.45 ± 0.35 h−1 Mpc and a power-law slope of γ = 1.72 ± 0.06 in the 0.4 < r < 50 h−1 Mpc range. But it is in the LRG angular correlation function that the strongest evidence for non-power-law features is found where a slope of γ = −2.17 ± 0.07 is seen at 1 < r < 10 h−1 Mpc with a flatter γ = −1.67 ± 0.07 slope apparent at r 1 h−1 Mpc scales. We use the simple power-law fit to the galaxy ξ(r), under the assumption of linear bias, to model the redshift-space distortions in the 2D redshift-space correlation function, ξ(σ, π). We fit for the LRG velocity dispersion, wz, the density parameter, Ωm and β(z), where β(z) = Ω0.6m/b and b is the linear bias parameter. We find values of wz = 330 km s−1, Ωm = 0.10+0.35−0.10 and β = 0.40 ± 0.05. The low values for wz and β reflect the high bias of the LRG sample. These high-redshift results, which incorporate the Alcock–Paczynski effect and the effects of dynamical infall, start to break the degeneracy between Ωm and β found in low-redshift galaxy surveys such as 2dFGRS. This degeneracy is further broken by introducing an additional external constraint, which is the value β(z = 0.1) = 0.45 from 2dFGRS, and then considering the evolution of clustering from z 0 to zLRG 0.55. With these combined methods we find Ωm(z = 0) = 0.30 ± 0.15 and β(z = 0.55) = 0.45 ± 0.05. Assuming these values, we find a value for b(z = 0.55) = 1.66 ± 0.35. We show that this is consistent with a simple ��high-peak’ bias prescription which assumes that LRGs have a constant comoving density and their clustering evolves purely under gravity.

Subfields: Astronomy and Astrophysics, Global and Planetary Change, Plant Science

View Paper: https://www.semanticscholar.org/paper/3074d87151f9a910368c796645f78f5b084dcd11

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Global and Planetary Change

In Plant Science

Citations in the corpus

FIVE-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE OBSERVATIONS: LIKELIHOODS AND PARAMETERS FROM THE WMAP DATA (2008, methodology): “The Ross et al. (2007) analysis of the 2dF-SDSS LRG sample find β = 0.45 ± 0.05 at z = 0.55.”
CLUSTERING OF LOW-REDSHIFT (z ⩽ 2.2) QUASARS FROM THE SLOAN DIGITAL SKY SURVEY (2008, methodology): “The space density of quasars is much smaller than that of galaxies, so the errors on the clustering measurement (e.g. ξ(rp, π)) are much larger than for galaxy surveys (cf. Hawkins et al. 2003; Zehavi et al. 2005; Ross et al. 2007; Guzzo et al. 2008).”
A 2.5 per cent measurement of the growth rate from small-scale redshift space clustering of SDSS-III CMASS galaxies (2014, methodology): “…catalogue, this method performs quite well at recovering the true clustering down to scales well below the BOSS fibre collision radius, and has been successfully applied in a number of other surveys (Hawkins et al. 2003; Li et al. 2006; Ross et al. 2007; White et al. 2011; de la Torre et al. 2013).”
The 2dF-SDSS LRG and QSO survey: QSO clustering and the L-z degeneracy (2006, methodology): “For comparison, also shown is the previously determined 2QZ ξ (s) (da Ângela et al. 2005), the 2SLAQ QSO ξ (s) and also the ξ (s) measurements of the 2SLAQ LRG sample (Ross et al. 2007).”
The clustering of intermediate-redshift quasars as measured by the Baryon Oscillation Spectroscopic Survey (2012, methodology): “The upweighting is derived by comparing the angular correlation function of all targets with c© 0000 RAS, MNRAS000, 000–000 that of the quasars for which we obtained redshifts (Hawkinset al. 2003; Li et al. 2006; Ross et al. 2007; White et al. 2011).”
The VIMOS Public Extragalactic Redshift Survey (VIPERS) - Galaxy clustering and redshift-space distortions at z ≃ 0.8 in the first data release (2013, result): “Our measurement of fσ8 is also in good agreement with previous measurements at lower redshifts from 2dFGRS (Hawkins et al. 2003), 2SLAQ (Ross et al. 2007), VVDS (Guzzo et al. 2008), SDSS LRG (Cabré & Gaztañaga 2009; Samushia et al. 2012), WiggleZ (Blake et al. 2012), BOSS (Reid et al. 2012), and…”
THE CLUSTERING OF MASSIVE GALAXIES AT z ∼ 0.5 FROM THE FIRST SEMESTER OF BOSS DATA (2010, background): “The weight is derived by comparing the angular correlation function of the entire photometric sample with that of the galaxies for which we obtained redshifts (Hawkins et al. 2003; Li et al. 2006; Ross et al. 2007).”
Large-Scale Anisotropic Correlation Function of SDSS Luminous Red Galaxies (2007, background): “On the other hand, the correlation analyses of the 2dF QSO survey placed constraints on the cosmological constant (Hoyle et al. 2002; Outram et al. 2004; da Ângela et al. 2005; see also Ross et al. 2007).”
MEASURING BARYON ACOUSTIC OSCILLATIONS ALONG THE LINE OF SIGHT WITH PHOTOMETRIC REDSHIFTS: THE PAU SURVEY (2008, background): “This is also the case in regions of high density, populated by LRG galaxies, and where σp could be larger, e.g., σp ∼ 400 km s−1/c ∼ 0.0013 for r > 5 Mpc h−1 (Ross et al. 2007).”
Red Galaxy Growth and the Halo Occupation Distribution (2008, result): “In Figure 5we plot the spatial clustering of z 0:8 red galaxies in Boötes (parameterized by r0) along with results from the recent literature at comparable redshifts (Brown et al. 2003; Wilson 2003; Meneux et al. 2006; Phleps et al. 2006; McCracken et al. 2008; Ross et al. 2007; Coil et al. 2008).”
Clustering of luminous red galaxies – IV. Baryon acoustic peak in the line-of-sight direction and a direct measurement of H(z) (2008, methodology): “Redshift distortions in the LRG’s and quasars at z ∼ 0.55 have been studied using the 2dF-SDSS LRG and QSO Survey (2SLAQ Cannon & etal 2007; Ross et al. 2007; da Ângela et al. 2008; Wake et al. 2008).”