Detection of the Baryon Acoustic Peak in the Large‐Scale Correlation Function of SDSS Luminous Red Galaxies

Abstract

We present the large-scale correlation function measured from a spectroscopic sample of 46,748 luminous red galaxies from the Sloan Digital Sky Survey. The survey region covers 0.72h −3 Gpc 3 over 3816 square degrees and 0.16 < z < 0.47, making it the best sample yet for the study of large-scale structure. We find a well-detected peak in the correlation function at 100h −1 Mpc separation that is an excellent match to the predicted shape and location of the imprint of the recombination-epoch acoustic oscillations on the low-redshift clustering of matter. This detection demonstrates the linear growth of structure by gravitational instability between z ≈ 1000 and the present and confirms a firm prediction of the standard cosmological theory. The acoustic peak provides a standard ruler by which we can measure the ratio of the distances to z = 0.35 and z = 1089 to 4% fractional accuracy and the absolute distance to z = 0.35 to 5% accuracy. From the overall shape of the correlation function, we measure the matter density Ω m h 2 to 8% and find agreement with the value from cosmic microwave background (CMB) anisotropies. Independent of the constraints provided by the CMB acoustic scale, we find Ω m = 0.273 ± 0.025 + 0.123(1 + w 0 ) + 0.137Ω K . Including the CMB acoustic scale, we find that the spatial curvature is Ω K = −0.010 ± 0.009 if the dark energy is a cosmological constant. More generally, our results provide a measurement of cosmological distance, and hence an argument for dark energy, based on a geometric method with the same simple physics as the microwave background anisotropies. The standard cosmological model convincingly passes these new and robust tests of its fundamental properties. Subject headings: cosmology: observations -large-scale structure of the universe -distance scalecosmological parameters -cosmic microwave background -galaxies: elliptical and lenticular, cD

Neutrino masses and cosmic radiation density: combined analysis

“…We use distant type Ia supernovae measured by the SuperNova Legacy Survey (SNLS) [9] and large-scale structure data from the 2dF [10] and SDSS [11,12] surveys. From the SDSS we also include the recent measurement of the baryon acoustic oscillation feature in the 2-point correlation function [13]. Finally, we include the precision measurements of the cosmic microwave background anisotropy from the WMAP experiment [4,14,15], as well as the smaller-scale measurement by the BOOMERANG experiment [16][17][18].…”

Constraining the relative velocity effect using the Baryon Oscillation Spectroscopic Survey

“…Measurements of the baryon acoustic scale in the distribution of galaxies have established themselves as one of the most powerful tools for precision cosmology (Eisenstein, Hu & Tegmark 1998;Percival et al 2001;Blake & Glazebrook 2003;Hu & Haiman 2003;Seo & Eisenstein 2003;Linder 2003;Eisenstein et al 2005;Cole et al 2005;Beutler et al 2011;Blake et al 2011;Alam et al 2016). With the most recent measurements of the BAO scale in the BOSS survey we have now reached 1% precision in two redshift bins (Alam et al 2016;Beutler et al 2016a;Ross et al 2016).…”

Detector Simulation and WIMP Search Analysis for the Cryogenic Dark Matter Search Experiment

“…Density fluctuations in the plasma composing the early universe gave rise to acoustic oscillations due to the competing effects of gravity, which drew matter to clump in overdense regions, and radiation pressure, which tended to disperse overdense regions. At decoupling, around 377,000 years after the Big Bang, the photon pressure driving these acoustic oscillations would have disappeared as the universe cooled sufficiently to al- [12] shows the correlation function times the square of the separation distance vs. the comoving separation distance. The acoustic feature is the spike at ≈ 100h −1 Mpc.…”

“…However, the situation is more favor- The colored lines show the expected curves for models with Ω m h 2 = 0.12, 0.13, and 0.14 in green, red, and blue, respectively, and a purely CDM model (Ω b = 0, so no acoustic peak))with Ω m h 2 = 0.105 in magenta. Figure from [12] of the equation of state parameter ω in the range 0 < z < 0.35 (ω = −1 in a dark energy dominated universe, and z is the redshift parameter) [12].…”