The VIMOS Public Extragalactic Redshift Survey. Measuring the growth rate of structure around cosmic voids
Abstract
We aim to develop a novel methodology for measuring thegrowth rate of structure around cosmic voids. We identified voids in the completed VIMOS Public Extragalactic Redshift Survey (VIPERS), using an algorithm based on searching for empty spheres. We measured the crosscorrelation between the centres of voids and the complete galaxy catalogue. The crosscorrelation function exhibits a clear anisotropy in both VIPERS fields (W1 and W4), which is characteristic of linear redshift space distortions. By measuring the projected crosscorrelation and then deprojecting it we are able to estimate the undistorted crosscorrelation function. We propose that given a sufficiently wellmeasured crosscorrelation function one should be able to measure the linear growth rate of structure by applying a simple linear Gaussian streaming model for the redshift space distortions (RSD). Our study of voids in 306 mock galaxy catalogues mimicking the VIPERS fields suggests that VIPERS is capable of measuring β, the ratio of the linear growth rate to the bias, with an error of around 25%. Applying our method to the VIPERS data, we find a value for the redshift space distortion parameter, β = 0.423_{0.108}^{+0.104} which, given the bias of the galaxy population we use, gives a linear growth rate of f σ_{8} = 0.296_{0.078}^{+0.075} at z = 0.727. These results are consistent with values observed in parallel VIPERS analyses that use standard techniques.
Based on observations collected at the European Southern Observatory, Cerro Paranal, Chile, using the Very Large Telescope under programs 182.A0886 and partly 070.A9007. Also based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the CanadaFranceHawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at TERAPIX and the Canadian Astronomy Data Centre as part of the CanadaFranceHawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 November 2017
 DOI:
 10.1051/00046361/201629678
 arXiv:
 arXiv:1611.07046
 Bibcode:
 2017A&A...607A..54H
 Keywords:

 largescale structure of Universe;
 cosmology: observations;
 cosmological parameters;
 gravitation;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 14 pages, 12 figures