Scale Dependence of Halo and Galaxy Bias: Effects in Real Space

By Rowan J. Smith, R. K. Sheth. 2006

190 citations recorded by the source corpus.

We examine the scale dependence of dark matter halo and galaxy clustering on very large scales (0.01<k[h Mpc{sup -1}]<0.15), due to nonlinear effects from dynamics and halo bias. We pursue a two line offensive: high-resolution numerical simulations are used to establish some old and some new results, and an analytic model is developed to understand their origins. Our simulations show: (i) that the z=0 dark matter power spectrum is suppressed relative to linear theory by {approx}5% on scales 0.05<k[h Mpc{sup -1}]<0.075; (ii) that, indeed, halo bias is nonlinear over the scales we probe and that the scale dependence is a strong function of halo mass. High mass haloes show no suppression of power on scales k<0.07[h Mpc{sup -1}], and only show amplification on smaller scales, whereas low mass haloes show strong, {approx}5%-10%, suppression over the range 0.05<k[h Mpc{sup -1}]<0.15. These results were primarily established through the use of the cross-power spectrum of dark matter and haloes, which circumvents the thorny issue of shot-noise correction. The halo-halo power spectrum, however, is highly sensitive to the shot-noise correction; we show that halo exclusion effects make this sub-Poissonian and a new correction is presented. Our results have special relevance for studies of themore » baryon acoustic oscillation features in the halo power spectra. Nonlinear mode-mode coupling: (i) damps these features on progressively larger scales as halo mass increases; (ii) produces small shifts in the positions of the peaks and troughs which depend on halo mass. We show that these effects on halo clustering are important over the redshift range relevant to such studies (0<z<2), and so will need to be accounted for when extracting information from precision measurements of galaxy clustering. Our analytic model is described in the language of the 'halo model.' The halo-halo clustering term is propagated into the nonlinear regime using '1-loop' perturbation theory and a nonlinear halo bias model. Galaxies are then inserted into haloes through the halo occupation distribution. We show that, with nonlinear bias parameters derived from simulations, this model produces predictions that are qualitatively in agreement with our numerical results. We then use it to show that the power spectra of red and blue galaxies depend differently on scale, thus underscoring the fact that proper modeling of nonlinear bias parameters will be crucial to derive reliable cosmological constraints. In addition to showing that the bias on very large scales is not simply linear, the model also shows that the halo-halo and halo-dark matter spectra do not measure precisely the same thing. This complicates interpretation of clustering in terms of the stochasticity of bias. However, because the shot-noise correction is nontrivial, evidence for this in the simulations is marginal.« less

Subfields: Astronomy and Astrophysics, Experimental and Cognitive Psychology

View Paper: https://www.semanticscholar.org/paper/45aca4c3d49f67b9446a5b32dc3ad66e08d2e79e

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Citations in the corpus

Clustering of luminous red galaxies – IV. Baryon acoustic peak in the line-of-sight direction and a direct measurement of H(z) (2008, result): “The latter is consistent with the findings of others Smith et al. (2007) that massive halos, by virtue of exclusion zones around them, do not have Poissonian shot noise.”
Massive neutrinos and the non‐linear matter power spectrum (2011, methodology): “This distinctive spoon shaped pre-virialization feature was also found by Brandbyge et al. (2008) and Viel et al. (2010), and in CDM simulations by Lokas et al. (1996); Smith et al. (2007).”
Non-linear evolution of cosmological structures in warm dark matter models (2011, methodology): “We then combine the estimates from each Fourier scale using a standard inverse variance weighted estimator (see e.g. Smith et al. 2007).”
Cosmology with massive neutrinos I: towards a realistic modeling of the relation between matter, haloes and galaxies (2013, methodology): “For this reason we have also used the alternative estimator, bhm(k) = Phm(k)/Pmm(k), where Phm(k) is the halomatter cross-power spectrum, which, being based on the cross power, is less sensitive to stochasticity [48–52].”
Constraining primordial non-Gaussianity with future galaxy surveys (2011, methodology): “Consistently, previous studies have shown that Smith et al. (2007) underestimates the convergence power spectrum by more than 20 % at l > 1000, while the halo model is reliable up to l ∼ 50, 000 (see Fig.”
INTENSITY MAPPING WITH CARBON MONOXIDE EMISSION LINES AND THE REDSHIFTED 21 cm LINE (2011, background): “The future CO surveys 11 The slight deficit of simulated power at high k likely results because the halos are not a perfect Poisson sample (e.g. Smith et al. 2007).”
Cosmological parameter constraints from galaxy-galaxy lensing and galaxy clustering with the SDSS DR7 (2012, background): “However, the bias is also scale-dependent on smaller scales (Cole et al. 2005; Tinker et al. 2005; Smith et al. 2007; Sánchez & Cole 2008), .”
Large-scale bias and efficient generation of initial conditions for nonlocal primordial non-Gaussianity (2011, background): “The former, when measured from a scatter plot between δh and δ, does not depend sensitively on the smoothing scale Rs (for Rs >∼ 30h −1 Mpc [52, 54]), but of course σ(2) is very sensitive to Rs, and thus the magnitude of this effect is uncertain(6).”
CLUSTERING OF LOW-REDSHIFT (z ⩽ 2.2) QUASARS FROM THE SLOAN DIGITAL SKY SURVEY (2008, background): “…be 20 h−1 Mpc, so that non-linear effects in the sample should be small due to the s2 weighting and for ease of comparison with Croom et al. (2005) and Blanton et al. (2006), Schulz & White (2006), Smith et al. (2007) and Coles & Erdogdu (2007) all suggest that bias is potentially scale dependent.”
Large-Scale Anisotropic Correlation Function of SDSS Luminous Red Galaxies (2007, background): “Recent work also suggests that the scale-dependent biasing poses a serious problem in analyzing galaxy surveys (e.g., Blanton et al. 2006; Percival et al. 2007b; Smith et al. 2007; Coles & Erdoğdu 2007; Sánchez & Cole 2008).”