J/MNRAS/449/835 Clustering of the SDSS DR7 main galaxy sample. I. (Ross+, 2015)
The clustering of the SDSS DR7 main Galaxy sample -
I. A 4 per cent distance measure at z=0.15.
Ross A.J., Samushia L., Howlett C., Percival W.J., Burden A., Manera M.
<Mon. Not. R. Astron. Soc., 449, 835-847 (2015)>
=2015MNRAS.449..835R 2015MNRAS.449..835R (SIMBAD/NED BibCode)
ADC_Keywords: Models ; Galaxies
Keywords: cosmology: observations - distance scale
Abstract:
We create a sample of spectroscopically identified galaxies with z<0.2
from the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7, Cat. II/294),
covering 6813 deg2. Galaxies are chosen to sample the highest mass
haloes, with an effective bias of 1.5, allowing us to construct 1000 mock
galaxy catalogues (described in Howlett et al. 2015MNRAS.449..848H 2015MNRAS.449..848H),
which we use to estimate statistical errors and test our methods. We use
an estimate of the gravitational potential to "reconstruct" the linear
density fluctuations, enhancing the baryon acoustic oscillation (BAO)
signal in the measured correlation function and power spectrum. Fitting
to these measurements, we determine
DV(zeff=0.15)=(664±25)(rd/rd, fid) Mpc; this is a better than
4 per cent distance measurement. This "fills the gap" in BAO distance
ladder between previously measured local and higher redshift measurements,
and affords significant improvement in constraining the properties of
dark energy. Combining our measurement with other BAO measurements from
Baryon Oscillation Spectroscopic Survey and 6-degree Field Galaxy Redshift
Survey galaxy samples provides a 15 per cent improvement in the
determination of the equation of state of dark energy and the value of
the Hubble parameter at z=0(H0). Our measurement is fully consistent
with the Planck results and the Λ cold dark matter concordance
cosmology, but increases the tension between Planck+BAO H0 determinations
and direct H0 measurements.
Description:
The Sloan Digital Sky Survey (SDSS; York et al. 2000AJ....120.1579Y 2000AJ....120.1579Y)
Data Release 7 (DR7; Abazajian et al. 2009, Cat. II/294) included a
flux-limited, low-redshift sample of galaxies with measured redshifts,
known as the "main galaxy sample" (MGS). We obtain the SDSS DR7 MGS data
from the value-added galaxy catalogues hosted by NYU1 (NYU-VAGC).
Galaxies in the NYU-VAGC safe0 catalogue occupy a total footprint of
7356 deg2. We use data only from the contiguous area in the North
Galactic cap and only occupying areas where the completeness, determined
ignoring galaxies not observed due to fibre collisions, is greater
than 0.9. These cuts reduce the footprint to 6813 deg2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 22 398 Consensus Δχ2 at each α,
defined by equation (7), gridded with a spacing
0.001
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See also:
II/294 : The SDSS Photometric Catalog, Release 7
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 6 F6.4 --- alpha [0.8015/1.1985] Scale dilation parameter α (1)
8- 22 F15.13 --- Dchi2 [0/9.40407] χ_2 difference Δχ2
(1)
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Note (1): For our fiducial cosmology (Flat, Omegamatter=0.31, h =0.67),
DVfid(z)=638.95 Mpc and rdfid=148.69 Mpc.
α=(DV(z)rdfid)/(DVfid(z)rd) (equation (7) in this paper).
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History:
From electronic version of the journal
References:
Howlett et al. Paper II. 2015MNRAS.449..848H 2015MNRAS.449..848H
(End) Tiphaine Pouvreau [CDS] 17-Jan-2020