We use the final catalogue of the VIMOS Public Extragalactic Redshift Survey (VIPERS) to measure the power spectrum of the galaxy distribution at high redshift, presenting results that extend beyond z = 1 for the first time. We apply a fast Fourier transform technique to four independent subvolumes comprising a total of 51 728 galaxies at 0.6 < z < 1.1 (out of the nearly 90 000 included in the whole survey). We concentrate here on the shape of the direction-averaged power spectrum in redshift space, explaining the level of modelling of redshift-space anisotropies and the anisotropic survey window function that are needed to deduce this in a robust fashion. We then use covariance matrices derived from a large ensemble of mock datasets in order to fit the spectral data. The results are well matched by a standard ΛCDM model, with density parameter ΩM h = 0.227+0.063-0.050 ΩMh=0.227-0.050+0.063 and baryon fraction fB=ΩB/ΩM=0.220+0.058-0.072fB=ΩB/ΩM=0.220-0.072+0.058. These inferences from the high-z galaxy distribution are consistent with results from local galaxy surveys, and also with the cosmic microwave background. Thus the ΛCDM model gives a good match to cosmic structure at all redshifts currently accessible to observational study.
The VIMOS Public Extragalactic Redshift Survey (VIPERS): The matter density and baryon fraction from the galaxy power spectrum at redshift 0.6 < z < 1.1
BRANCHINI, ENZO FRANCO;
2017
Abstract
We use the final catalogue of the VIMOS Public Extragalactic Redshift Survey (VIPERS) to measure the power spectrum of the galaxy distribution at high redshift, presenting results that extend beyond z = 1 for the first time. We apply a fast Fourier transform technique to four independent subvolumes comprising a total of 51 728 galaxies at 0.6 < z < 1.1 (out of the nearly 90 000 included in the whole survey). We concentrate here on the shape of the direction-averaged power spectrum in redshift space, explaining the level of modelling of redshift-space anisotropies and the anisotropic survey window function that are needed to deduce this in a robust fashion. We then use covariance matrices derived from a large ensemble of mock datasets in order to fit the spectral data. The results are well matched by a standard ΛCDM model, with density parameter ΩM h = 0.227+0.063-0.050 ΩMh=0.227-0.050+0.063 and baryon fraction fB=ΩB/ΩM=0.220+0.058-0.072fB=ΩB/ΩM=0.220-0.072+0.058. These inferences from the high-z galaxy distribution are consistent with results from local galaxy surveys, and also with the cosmic microwave background. Thus the ΛCDM model gives a good match to cosmic structure at all redshifts currently accessible to observational study.
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