The XXL Survey

XX. The 365 cluster catalogue^★,★★

¹ Aix Marseille Univ., CNRS, CNES, LAM, Marseille, France
e-mail: christophe.adami@lam.fr
² INAF – Osservatorio astronomico di Padova, Vicolo Osservatorio 5, 35122 Padova, Italy
³ Laboratoire AIM, CEA/DSM/IRFU/SAp, CEA Saclay, 91191 Gif-sur-Yvette, France
⁴ Argelander Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany
⁵ European Southern Observatory, Alonso de Cordova 3107, Vitacura, 19001 Casilla, Santiago 19, Chile
⁶ Departamento de Astronomía, DCNE-CGT, Universidad de Guanajuato; Callejón de Jalisco, s/n, Col. Valenciana, 36240 Guanajuato, Gto., Mexico
⁷ School of Physics, HH Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL, UK
⁸ INAF – IASF Milano, via Bassini 15, 20133 Milano, Italy
⁹ Department of Astronomy, University of Geneva, Ch. d’Écogia 16, 1290 Versoix, Switzerland
¹⁰ Aristotle University of Thessaloniki, Physics Department, Thessaloniki 54124, Greece
¹¹ Australian Astronomical Observatory, PO Box 915, North Ryde 1670, Australia
¹² Laboratoire Lagrange, UMR 7293, Université de Nice Sophia Antipolis, CNRS, Observatoire de la Côte d’Azur, 06304 Nice, France
¹³ Department of Physics, University of Oxford, Oxford OX1 3PU, UK
¹⁴ Merton College, Oxford OX1 4JD, UK
¹⁵ School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
¹⁶ Astrophysics and Space Research Group, School of Physics and Astronomy, Univ. of Birmingham, Birmingham B15 2TT, UK
¹⁷ Macquarie University, NSW 2109, Australia
¹⁸ ICRAR, 1 Turner Avenue, Technology Park, Bentley, Western Australia 6102, Australia
¹⁹ University of St Andrews, College Gate, St Andrews, KY16 9AJ Fife, UK
²⁰ Astrophysics Research Institute, Liverpool John Moores Univ., IC2, Liverpool Science Park, 146 Brownlow Hill, Liverpool L3 5RF, UK
²¹ Monash University, Victoria 3800, Australia
²² Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
²³ Max-Planck-Institut für Kernphysik, PO Box 103980, 69029 Heidelberg, Germany
²⁴ Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
²⁵ Department of Astronomy, University of Michigan, Ann Arbor, MI 48109, USA
²⁶ Department of Physics, University of Michigan, Ann Arbor, MI 48109, USA
²⁷ INAF, Osservatorio Astronomico di Bologna, via Pietro Gobetti 93/3, 40129 Bologna, Italy
²⁸ Chalmers University of Technology, Department of Space, Environment, and Earth, Onsala Space Observatory, 439 92 Onsala, Sweden
²⁹ INAF – Osservatorio Astronomico di Brera, Via Brera 28, 20122 Milano, via E. Bianchi 46, 20121 Merate, Italy
³⁰ Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 1A1, Canada
³¹ Department of Physics and Astronomy, University of Padova, Vicolo Osservatorio 3, 35122 Padova, Italy
³² European Space Astronomy Centre (ESA/ESAC), Operations Department, Villanueva de la Canãda, Madrid, Spain
³³ Univ. degli studi di Milano, via G. Celoria 16, 20133 Milano, Italy
³⁴ Dipartimento di Fisica e Astronomia (DIFA), Università di Bologna, viale Berti Pichat 6/2, 40127 Bologna, Italy
³⁵ INFN, Sezione di Bologna, viale Berti Pichat 6/2, 40127 Bologna, Italy
³⁶ National Centre for Nuclear Research, ul. Hoza 69, 00-681 Warszawa, Poland
³⁷ IRAP Université de Toulouse, CNRS, UPS, Toulouse, France
³⁸ Astronomical Observatory of the Jagiellonian University, Orla 171, 30-001 Cracow, Poland
³⁹ INAF – IASF Bologna, via Gobetti 101, 40129 Bologna, Italy
⁴⁰ Aix-Marseille Université – Pharo, 58 bd Charles Livon Jardin du Pharo, 13007 Marseille, France
⁴¹ Department of Astronomy and Space Sciences, Faculty of Science, Istanbul University, 34119 Istanbul, Turkey
⁴² INFN, Sezione di Bologna, viale Berti Pichat 6/2, 40127 Bologna, Italy
⁴³ Center for Astrophysics and Space Astronomy, Department of Astrophysical and Planetary Science, University of Colorado, Boulder, CO 80309, USA
⁴⁴ NASA Ames Research Center, Moffett Field, CA 94035, USA
⁴⁵ National Observatory of Athens, Lofos Nymfon, 11851 Athens, Greece
⁴⁶ Centre for Extragalactic Astronomy, Department of Physics, Durham University, South Road, Durham DH1 3LE, UK

Received: 20 July 2017
Accepted: 27 November 2017

Abstract

Context. In the currently debated context of using clusters of galaxies as cosmological probes, the need for well-defined cluster samples is critical.

Aims. The XXL Survey has been specifically designed to provide a well characterised sample of some 500 X-ray detected clusters suitable for cosmological studies. The main goal of present article is to make public and describe the properties of the cluster catalogue in its present state, as well as of associated catalogues of more specific objects such as super-clusters and fossil groups.

Methods. Following from the publication of the hundred brightest XXL clusters, we now release a sample containing 365 clusters in total, down to a flux of a few 10⁻¹⁵ erg s⁻¹ cm⁻² in the [0.5–2] keV band and in a 1′ aperture. This release contains the complete subset of clusters for which the selection function is well determined plus all X-ray clusters which are, to date, spectroscopically confirmed. In this paper, we give the details of the follow-up observations and explain the procedure adopted to validate the cluster spectroscopic redshifts. Considering the whole XXL cluster sample, we have provided two types of selection, both complete in a particular sense: one based on flux-morphology criteria, and an alternative based on the [0.5–2] keV flux within 1 arcmin of the cluster centre. We have also provided X-ray temperature measurements for 80% of the clusters having a flux larger than 9 × 10⁻¹⁵ erg s⁻¹ cm⁻².

Results. Our cluster sample extends from z ~ 0 to z ~ 1.2, with one cluster at z ~ 2. Clusters were identified through a mean number of six spectroscopically confirmed cluster members. The largest number of confirmed spectroscopic members in a cluster is 41. Our updated luminosity function and luminosity–temperature relation are compatible with our previous determinations based on the 100 brightest clusters, but show smaller uncertainties. We also present an enlarged list of super-clusters and a sample of 18 possible fossil groups.

Conclusions. This intermediate publication is the last before the final release of the complete XXL cluster catalogue when the ongoing C2 cluster spectroscopic follow-up is complete. It provides a unique inventory of medium-mass clusters over a 50 deg² area out to z ~ 1.