Planck intermediate results

IV. The XMM-Newton validation programme for new Planck galaxy clusters

¹ APC, AstroParticule et Cosmologie, Université Paris Diderot, CNRS/IN2P3, CEA/lrfu, Observatoire de Paris, Sorbonne Paris Cité, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France
² Aalto University Metsähovi Radio Observatory, Metsähovintie 114, 02540 Kylmälä, Finland
³ Academy of Sciences of Tatarstan, Bauman Str., 20, 420111 Kazan, Republic of Tatarstan, Russia
⁴ Agenzia Spaziale Italiana Science Data Center, c/o ESRIN, via Galileo Galilei, Frascati, Italy
⁵ Agenzia Spaziale Italiana, Viale Liegi 26, Roma, Italy
⁶ Astrophysics Group, Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, UK
⁷ Atacama Large Millimeter/submillimeter Array, ALMA Santiago Central Offices, Alonso de Cordova 3107, Vitacura, Casilla 763 0355, Santiago, Chile
⁸ CITA, University of Toronto, 60 St. George St., Toronto, ON M5S 3H8, Canada
⁹ CNRS, IRAP, 9 Av. colonel Roche, BP 44346, 31028 Toulouse Cedex 4, France
¹⁰ California Institute of Technology, Pasadena, California, USA
¹¹ Centre of Mathematics for Applications, University of Oslo, Blindern, Oslo, Norway
¹² Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal
¹³ Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Plaza San Juan 1, planta 2, 44001 Teruel, Spain
¹⁴ Computational Cosmology Center, Lawrence Berkeley National Laboratory, Berkeley, California, USA
¹⁵ DSM/Irfu/SPP, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
¹⁶ DTU Space, National Space Institute, Juliane Mariesvej 30, Copenhagen, Denmark
¹⁷ Département de Physique Théorique, Université de Genève, 24 Quai E. Ansermet, 1211 Genève 4, Switzerland
¹⁸ Departamento de Física, Universidad de Oviedo, Avda. Calvo Sotelo s/n, Oviedo, Spain
¹⁹ Department of Astronomy and Geodesy, Kazan Federal University, Kremlevskaya Str., 18, 420008 Kazan, Russia
²⁰ Department of Physics & Astronomy, University of British Columbia,6224 Agricultural Road, Vancouver, British Columbia, Canada
²¹ Department of Physics and Astronomy, Dana and David Dornsife College of Letter, Arts and Sciences, University of Southern California, Los Angeles, CA 90089, USA
²² Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH, UK
²³ Department of Physics, Gustaf Hällströmin katu 2a, University of Helsinki, Helsinki, Finland
²⁴ Department of Physics, Princeton University, Princeton, New Jersey, USA
²⁵ Department of Physics, University of California, Berkeley, California, USA
²⁶ Department of Physics, University of California, One Shields Avenue, Davis, California, USA
²⁷ Department of Physics, University of California, Santa Barbara, California, USA
²⁸ Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois, USA
²⁹ Department of Statistics, Purdue University, 250 N. University Street, West Lafayette, Indiana, USA
³⁰ Dipartimento di Fisica e Astronomia G. Galilei, Università degli Studi di Padova, via Marzolo 8, 35131 Padova, Italy
³¹ Dipartimento di Fisica, Università La Sapienza, P.le A. Moro 2, Roma, Italy
³² Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, Milano, Italy
³³ Dipartimento di Fisica, Università degli Studi di Trieste, via A. Valerio 2, Trieste, Italy
³⁴ Dipartimento di Fisica, Università di Ferrara, via Saragat 1, 44122 Ferrara, Italy
³⁵ Dipartimento di Fisica, Università di Roma Tor Vergata, via della Ricerca Scientifica 1, Roma, Italy
³⁶ Dipartimento di Matematica, Università di Roma Tor Vergata, via della Ricerca Scientifica 1, Roma, Italy
³⁷ Discovery Center, Niels Bohr Institute, Blegdamsvej 17, Copenhagen, Denmark
³⁸ Dpto. Astrofísica, Universidad de La Laguna (ULL), 38206, La Laguna Tenerife, Spain
³⁹ European Southern Observatory, ESO Vitacura, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago, Chile
⁴⁰ European Space Agency, ESAC, Camino bajo del Castillo s/n, Urbanización Villafranca del Castillo, Villanueva de la Cañada, Madrid, Spain
⁴¹ European Space Agency, ESAC, Planck Science Office, Camino bajo del Castillo s/n, Urbanización Villafranca del Castillo, Villanueva de la Cañada, Madrid, Spain
⁴² European Space Agency, ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands
⁴³ GEPI, Observatoire de Paris, Section de Meudon, 5 place J. Janssen, 92195 Meudon Cedex, France
⁴⁴ Helsinki Institute of Physics, Gustaf Hällströmin katu 2, University of Helsinki, Helsinki, Finland
⁴⁵ INAF – Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, Padova, Italy
⁴⁶ INAF – Osservatorio Astronomico di Roma, via di Frascati 33, Monte Porzio Catone, Italy
⁴⁷ INAF – Osservatorio Astronomico di Trieste, via G.B. Tiepolo 11, Trieste, Italy
⁴⁸ INAF Istituto di Radioastronomia, via P. Gobetti 101, 40129 Bologna, Italy
⁴⁹ INAF/IASF Bologna, via Gobetti, 101, Bologna, Italy
⁵⁰ INAF/IASF Milano, via E. Bassini 15, Milano, Italy
⁵¹ INFN, Sezione di Roma 1, Università di Roma Sapienza, Piazzale Aldo Moro 2, 00185 Roma, Italy
⁵² INRIA, Laboratoire de Recherche en Informatique, Université Paris-Sud 11, Bâtiment 490, 91405 Orsay Cedex, France
⁵³ IPAG: Institut de Planétologie et d’Astrophysique de Grenoble, Université Joseph Fourier, Grenoble 1 / CNRS-INSU, UMR 5274, 38041 Grenoble, France
⁵⁴ IUCAA, Post Bag 4, Ganeshkhind, Pune University Campus, 411 007 Pune, India
⁵⁵ Imperial College London, Astrophysics group, Blackett Laboratory, Prince Consort Road, London SW7 2AZ, UK
⁵⁶ Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, USA
⁵⁷ Institut Néel, CNRS, Université Joseph Fourier Grenoble I, 25 rue des Martyrs, Grenoble, France
⁵⁸ Institut Universitaire de France, 103 Bd Saint-Michel, 75005 Paris, France
⁵⁹ Institut d’Astrophysique Spatiale, CNRS UMR8617 Université Paris-Sud 11, Bâtiment 121, Orsay, France
⁶⁰ Institut d’Astrophysique de Paris, CNRS UMR7095, 98bis boulevard Arago, 75014 Paris, France
⁶¹ Institute for Space Sciences, Bucharest-Magurale, Romania
⁶² Institute of Astro and Particle Physics, Technikerstrasse 25/8, University of Innsbruck, 6020 Innsbruck, Austria
⁶³ Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan
⁶⁴ Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
⁶⁵ Institute of TheoreticalAstrophysics, University of Oslo, Blindern, Oslo, Norway
⁶⁶ Instituto de Astrofísica de Canarias, C/Vía Láctea s/n, La Laguna, Tenerife, Spain
⁶⁷ Instituto de Física de Cantabria (CSIC-Universidad de Cantabria), Avda. de los Castros s/n, Santander, Spain
⁶⁸ Istituto di Fisica del Plasma, CNR-ENEA-EURATOM Association, via R. Cozzi 53, Milano, Italy
⁶⁹ Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California, USA
⁷⁰ Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
⁷¹ Kavli Institute for Cosmology Cambridge, Madingley Road, Cambridge CB3 0HA, UK
⁷² LAL, Université Paris-Sud, CNRS/IN2P3, Orsay, France
⁷³ LERMA, CNRS, Observatoire de Paris, 61 avenue de l’Observatoire, Paris, France
⁷⁴ Laboratoire AIM, IRFU/Service d’Astrophysique – CEA/DSM – CNRS – Université Paris Diderot, Bât. 709, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
e-mail: jessica.democles@cea.fr
⁷⁵ Laboratoire de Physique Subatomique et de Cosmologie, Université Joseph Fourier Grenoble I, CNRS/IN2P3, Institut National Polytechnique de Grenoble, 53 rue des Martyrs, 38026 Grenoble Cedex, France
⁷⁶ Laboratoire de Physique Théorique, Université Paris-Sud 11 & CNRS, Bâtiment 210, 91405 Orsay, France
⁷⁷ Lawrence Berkeley National Laboratory, Berkeley, California, USA
⁷⁸ Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching, Germany
⁷⁹ Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstraße, 85748 Garching, Germany
⁸⁰ Niels Bohr Institute, Blegdamsvej 17, Copenhagen, Denmark
⁸¹ Observational Cosmology, Mail Stop 367-17, California Institute of Technology, Pasadena, CA, 91125, USA
⁸² Optical Science Laboratory, University College London, Gower Street, London, UK
⁸³ SISSA, Astrophysics Sector, via Bonomea 265, 34136 Trieste, Italy
⁸⁴ SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK
⁸⁵ School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA, UK
⁸⁶ Space Research Institute (IKI), Russian Academy of Sciences, Profsoyuznaya Str, 84/32, 117997 Moscow, Russia
⁸⁷ Space Sciences Laboratory, University of California, Berkeley, California, USA
⁸⁸ Stanford University, Dept of Physics, Varian Physics Bldg, 382 via Pueblo Mall, Stanford, California, USA
⁸⁹ UPMC Univ. Paris 6, UMR7095, 98bis boulevard Arago, 75014 Paris, France
⁹⁰ Université Denis Diderot (Paris 7), 75205 Paris Cedex 13, France
⁹¹ Université de Toulouse, UPS-OMP, IRAP, 31028 Toulouse Cedex 4, France
⁹² University Observatory, Ludwig Maximilian University of Munich, Scheinerstrasse 1, 81679 Munich, Germany
⁹³ University of Granada, Departamento de Física Teórica y del Cosmos, Facultad de Ciencias, Granada, Spain
⁹⁴ University of Miami, Knight Physics Building, 1320 Campo Sano Dr., Coral Gables, Florida, USA
⁹⁵ Warsaw University Observatory, Aleje Ujazdowskie 4, 00-478 Warszawa, Poland

Received: 2 May 2012
Accepted: 29 July 2012

Abstract

We present the final results from the XMM-Newton validation follow-up of new Planck galaxy cluster candidates. We observed 15 new candidates, detected with signal-to-noise ratios between 4.0 and 6.1 in the 15.5-month nominal Planck survey. The candidates were selected using ancillary data flags derived from the ROSAT All Sky Survey (RASS) and Digitized Sky Survey all-sky maps, with the aim of pushing into the low SZ flux, high-z regime and testing RASS flags as indicators of candidate reliability. Fourteen new clusters were detected by XMM-Newton, ten single clusters and two double systems. Redshifts from X-ray spectroscopy lie in the range 0.2 to 0.9, with six clusters at z > 0.5. Estimated masses (M₅₀₀) range from 2.5 × 10¹⁴ to 8 × 10¹⁴ M_⊙. We discuss our results in the context of the full XMM-Newton validation programme, in which 51 new clusters have been detected. This includes four double and two triple systems, some of which are chance projections on the sky of clusters at different redshifts. We find thatassociation with a source from the RASS-Bright Source Catalogue is a robust indicator of the reliability of a candidate, whereas association with a source from the RASS-Faint Source Catalogue does not guarantee that the SZ candidate is a bona fide cluster. Nevertheless, most Planck clusters appear in RASS maps, with a significance greater than 2σ being a good indication that the candidate is a real cluster. Candidate validation from association with SDSS galaxy overdensity at z > 0.5 is also discussed. The full sample gives a Planck sensitivity threshold of Y₅₀₀ ~ 4 × 10^-4 arcmin², with indication for Malmquist bias in the Y_X–Y₅₀₀ relation below this threshold. The corresponding mass threshold depends on redshift. Systems with M₅₀₀ > 5 × 10¹⁴ M_⊙ at z > 0.5 are easily detectable with Planck. The newly-detected clusters follow the Y_X–Y₅₀₀ relation derived from X-ray selected samples. Compared to X-ray selected clusters, the new SZ clusters have a lower X-ray luminosity on average for their mass. There is no indication of departure from standard self-similar evolution in the X-ray versus SZ scaling properties. In particular, there is no significant evolution of the Y_X/Y₅₀₀ ratio.