The VIMOS Public Extragalactic Redshift Survey (VIPERS). An unbiased estimate of the growth rate of structure at ⟨z⟩ = 0.85 using the clustering of luminous blue galaxies
Articolo
Data di Pubblicazione:
2018
Citazione:
The VIMOS Public Extragalactic Redshift Survey (VIPERS). An unbiased estimate of the growth rate of structure at ⟨z⟩ = 0.85 using the clustering of luminous blue galaxies / F.G. Mohammad, B.R. Granett, L. Guzzo, J. Bel, E. Branchini, S. de la Torre, L. Moscardini, J.A. Peacock, M. Bolzonella, B. Garilli, M. Scodeggio, U. Abbas, C. Adami, D. Bottini, A. Cappi, O. Cucciati, I. Davidzon, P. Franzetti, A. Fritz, A. Iovino, J. Krywult, V. Le Brun, O. Le Fèvre, D. Maccagni, K. Małek, F. Marulli, M. Polletta, A. Pollo, L.A.M. Tasca, R. Tojeiro, D. Vergani, A. Zanichelli, S. Arnouts, J. Coupon, G. De Lucia, O. Ilbert, T. Moutard. - In: ASTRONOMY & ASTROPHYSICS. - ISSN 0004-6361. - 610(2018), pp. A59.1-A59.20. [10.1051/0004-6361/201731685]
Abstract:
We used the VIMOS Public Extragalactic Redshift Survey (VIPERS) final data release (PDR-2) to investigate the performance of colour-selected populations of galaxies as tracers of linear large-scale motions. We empirically selected volume-limited samples of blue and red galaxies as to minimise the systematic error on the estimate of the growth rate of structure f sigma(8) from the anisotropy of the two-point correlation function. To this end, rather than rigidly splitting the sample into two colour classes we defined the red or blue fractional contribution of each object through a weight based on the (U-V) colour distribution. Using mock surveys that are designed to reproduce the observed properties of VIPERS galaxies, we find the systematic error in recovering the fiducial value of f sigma(8) to be minimised when using a volume-limited sample of luminous blue galaxies. We modelled non-linear corrections via the Scoccimarro extension of the Kaiser model (with updated fitting formulae for the velocity power spectra), finding systematic errors on f sigma(8) of below 1-2%, using scales as small as 5 h(-1) Mpc. We interpret this result as indicating that selection of luminous blue galaxies maximises the fraction that are central objects in their dark matter haloes; this in turn minimises the contribution to the measured xi(r(p), pi) from the 1-halo term, which is dominated by non-linear motions. The gain is inferior if one uses the full magnitude-limited sample of blue objects, consistent with the presence of a significant fraction of blue, fainter satellites dominated by non-streaming, orbital velocities. We measured a value of f sigma(8) = 0.45 +/- 0.11 over the single redshift range 0.6 <= z <= 1.0, corresponding to an effective redshift for the blue galaxies < z > = 0.85. Including in the likelihood the potential extra information contained in the blue-red galaxy cross-correlation function does not lead to an appreciable improvement in the error bars, while it increases the systematic error.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
cosmology: observations; large-scale structure of Universe; galaxies: high-redshift; galaxies: statistics
Elenco autori:
F.G. Mohammad, B.R. Granett, L. Guzzo, J. Bel, E. Branchini, S. de la Torre, L. Moscardini, J.A. Peacock, M. Bolzonella, B. Garilli, M. Scodeggio, U. Abbas, C. Adami, D. Bottini, A. Cappi, O. Cucciati, I. Davidzon, P. Franzetti, A. Fritz, A. Iovino, J. Krywult, V. Le Brun, O. Le Fèvre, D. Maccagni, K. Małek, F. Marulli, M. Polletta, A. Pollo, L.A.M. Tasca, R. Tojeiro, D. Vergani, A. Zanichelli, S. Arnouts, J. Coupon, G. De Lucia, O. Ilbert, T. Moutard
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