Abstract
We present a one per cent measurement of the cosmic distance scale from the
detections of the baryon acoustic oscillations in the clustering of galaxies
from the Baryon Oscillation Spectroscopic Survey (BOSS), which is part of the
Sloan Digital Sky Survey III (SDSS-III). Our results come from the Data Release
11 (DR11) sample, containing nearly one million galaxies and covering
approximately 8500 square degrees and the redshift range $0.2<z<0.7$. We also
compare these results with those from the publicly released DR9 and DR10
samples. Assuming a concordance $Łambda$CDM cosmological model, the DR11
sample covers a volume of 13Gpc$^3$ and is the largest region of the Universe
ever surveyed at this density. We measure the correlation function and power
spectrum, including density-field reconstruction of the baryon acoustic
oscillation (BAO) feature. The acoustic features are detected at a significance
of over $7\sigma$ in both the correlation function and power spectrum. Fitting
for the position of the acoustic features measures the distance relative to the
sound horizon at the drag epoch, $r_d$, which has a value of $r_d,\rm
fid=149.28$Mpc in our fiducial cosmology. We find $D_V=(1264\pm25\,\rm
Mpc)(r_d/r_d,fid)$ at $z=0.32$ and $D_V=(2056\pm20\,\rm
Mpc)(r_d/r_d,fid)$ at $z=0.57$. At 1.0 per cent, this latter measure
is the most precise distance constraint ever obtained from a galaxy survey.
Separating the clustering along and transverse to the line-of-sight yields
measurements at $z=0.57$ of $D_A=(1421\pm20\,Mpc)(r_d/r_d,fid)$
and $H=(96.8\pm3.4\,km/s/Mpc)(r_d,fid/r_d)$. Our measurements of
the distance scale are in good agreement with previous BAO measurements and
with the predictions from cosmic microwave background data for a spatially flat
cold dark matter model with a cosmological constant.
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