@article{0938b29a341947678731d96eed90c46f,
title = "The XXL Survey: II. the bright cluster sample: Catalogue and luminosity function",
abstract = "Context. The XXL Survey is the largest survey carried out by the XMM-Newton satellite and covers a total area of 50 square degrees distributed over two fields. It primarily aims at investigating the large-scale structures of the Universe using the distribution of galaxy clusters and active galactic nuclei as tracers of the matter distribution. The survey will ultimately uncover several hundreds of galaxy clusters out to a redshift of ∼2 at a sensitivity of ∼10-14 erg s-1 cm-2 in the [0.5-2] keV band. Aims. This article presents the XXL bright cluster sample, a subsample of 100 galaxy clusters selected from the full XXL catalogue by setting a lower limit of 3 × 10-14 erg s-1 cm-2 on the source flux within a 1' aperture. Methods. The selection function was estimated using a mixture of Monte Carlo simulations and analytical recipes that closely reproduce the source selection process. An extensive spectroscopic follow-up provided redshifts for 97 of the 100 clusters. We derived accurate X-ray parameters for all the sources. Scaling relations were self-consistently derived from the same sample in other publications of the series. On this basis, we study the number density, luminosity function, and spatial distribution of the sample. Results. The bright cluster sample consists of systems with masses between M500 = 7 × 1013 and 3 × 1014 M⊙, mostly located between z = 0.1 and 0.5. The observed sky density of clusters is slightly below the predictions from the WMAP9 model, and significantly below the prediction from the Planck 2015 cosmology. In general, within the current uncertainties of the cluster mass calibration, models with higher values of σ8 and/or ΩM appear more difficult to accommodate. We provide tight constraints on the cluster differential luminosity function and find no hint of evolution out to z ∼1. We also find strong evidence for the presence of large-scale structures in the XXL bright cluster sample and identify five new superclusters.",
keywords = "Cosmological parameters, Galaxies: clusters: intracluster medium, Large-scale structure of Universe, Surveys, X-rays: galaxies: clusters",
author = "F. Pacaud and N. Clerc and Giles, {P. A.} and C. Adami and T. Sadibekova and M. Pierre and Maughan, {B. J.} and M. Lieu and {Le F{\`e}vre}, {J. P.} and S. Alis and B. Altieri and F. Ardila and I. Baldry and C. Benoist and M. Birkinshaw and L. Chiappetti and J. D{\'e}mocl{\`e}s and D. Eckert and Evrard, {A. E.} and L. Faccioli and F. Gastaldello and L. Guennou and C. Horellou and A. Iovino and E. Koulouridis and {Le Brun}, V. and C. Lidman and J. Liske and S. Maurogordato and F. Menanteau and M. Owers and B. Poggianti and D. Pomar{\`e}de and E. Pompei and Ponman, {T. J.} and D. Rapetti and Reiprich, {T. H.} and Smith, {G. P.} and R. Tuffs and P. Valageas and I. Valtchanov and Willis, {J. P.} and F. Ziparo",
note = "Funding Information: Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA. Based on observations made with ESO Telescopes at the La Silla and Paranal Observatories under programme ID 089.A-0666 and LP191.A-0268. XXL is an international project based around an XMM Very Large Programme surveying two 25 deg2 extragalactic fields at a depth of ~5 × 10-15 erg s-1 cm-2 in [0.5-2] keV. The XXL website is http://irfu. cea.fr/xxl. Multiband information and spectroscopic follow-up of the X-ray sources are obtained through a number of survey programmes, summarised at http://xxlmultiwave.pbworks.com/. This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This research has made use of Aladin sky atlas and simbad database, both developed at CDS, Strasbourg Observatory, France. In particular, we would like to thank Thomas Boch for his help with Aladin Lite. F.P. acknowledges support from the BMWi/DLR grant 50 OR 1117, the DFG grant RE 1462-6 and the DfG Transregio Programme TR33. T.R. acknowledges support from the DFG Heisenberg grant RE 1462- 5. The Saclay group acknowledges long-term support by the Centre National d'{\'E}tudes Spatiales (CNES). The XXL team would also like to thank the VLT support astronomers C. Hummel and N. Neumayer for their dedicated help in the implementation of the XXL ESO Large Program and with the data reduction. The Dark Cosmology Centre is funded by the Danish National Research Foundation. B.J.M., P.A.G. and M.B. acknowledge support from STFC grants ST/J001414/1 and ST/M000907/1. Publisher Copyright: {\textcopyright} ESO, 2016.",
year = "2016",
doi = "10.1051/0004-6361/201526891",
language = "English (US)",
volume = "592",
journal = "Astronomy and Astrophysics",
issn = "0004-6361",
publisher = "EDP Sciences",
}