@article{10902/28454,
year = {2011},
month = {12},
url = {https://hdl.handle.net/10902/28454},
abstract = {We present the XMM-Newton follow-up for confirmation of Planck cluster candidates. Twenty-five candidates have been observed to date using snapshot (~10ks) exposures, ten as part of a pilot programme to sample a low range of signal-to-noise ratios (4 < S/N < 6), and a further 15 in a programme to observe a sample of S/N > 5 candidates. The sensitivity and spatial resolution of XMM-Newton allows unambiguous discrimination between clusters and false candidates. The 4 false candidates have S/N ? 4.1. A total of 21 candidates are confirmed as extended X-ray sources. Seventeen are single clusters, the majority of which are found to have highly irregular and disturbed morphologies (about  ~70%). The remaining four sources are multiple systems, including the unexpected discovery of a supercluster at z = 0.45. For 20 sources we are able to derive a redshift estimate from the X-ray Fe K line (albeit of variable quality). The new clusters span the redshift range 0.09 ? z ? 0.54, with a median redshift of z ~ 0.37. A first determination is made of their X-ray properties including the characteristic size, which is used to improve the estimate of the SZ Compton parameter, Y500. The follow-up validation programme has helped to optimise the Planck candidate selection process. It has also provided a preview of the X-ray properties of these newly-discovered clusters, allowing comparison with their SZ properties, and to the X-ray and SZ properties of known clusters observed in the Planck survey. Our results suggest that Planck may have started to reveal a non-negligible population of massive dynamically perturbed objects that is under-represented in X-ray surveys. However, despite their particular properties, these new clusters appear to follow the Y500?YX relation established for X-ray selected objects, where YX is the product of the gas mass and temperature.},
organization = {The Planck Collaboration thanks Norbert Schartel for his support to the validation process and granting discretionary time for the observation of Planck cluster candidates. The present work is based: on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and the USA (NASA); and on observations made with the IAC80 telescope operated on the island
of Tenerife by the Instituto de Astrofísica de Canarias (IAC) in the Spanish Observatorio del Teide. This research has made use of the following databases: SIMBAD, operated at CDS, Strasbourg, France; the NED database, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration; BAX, which is operated by the Laboratoire d’Astrophysique de Tarbes-Toulouse (LATT), under contract with the Centre National d’Études Spatiales (CNES); and the SZ repository operated by IAS Data and Operation Center (IDOC) under contract with CNES. A description of the Planck Collaboration and a list of its members, indicating which technical or scientific activities they have been involved in, can be found at http://www.rssd.esa.int/Planck_Collaboration. The Planck Collaboration acknowledges the support of: ESA; CNES and CNRS/INSU-IN2P3-INP (France); ASI, CNR, and INAF (Italy); NASA and DoE (USA); STFC and UKSA (UK); CSIC, MICINN and JA (Spain); Tekes, AoF and CSC (Finland); DLR and MPG (Germany); CSA (Canada); DTU Space (Denmark); SER/SSO (Switzerland); RCN (Norway); SFI
(Ireland); FCT/MCTES (Portugal); and DEISA (EU).},
publisher = {EDP Sciences},
publisher = {Astronomy and Astrophysics, 2011, 536, A9},
title = {Planck early results. IX. XMM-Newton follow-up for validation of Planck cluster candidates},
author = {Aghanim, Nabila and Arnaud, M. and Ashdown, Mark and Aumont, J. and Baccigalupi, C. and Balbi, A. and Banday, A. J. and Barreiro Vilas, Rita Belén and Bartelmann, M. and Bartlett, J. G. and Battaner, E. and Benabed, K. and Benoît, A. and Bernard, J.-P. and Bersanelli, M. and Diego Rodríguez, José María and Herranz Muñoz, Diego and López-Caniego Alcarria, Marcos and Martínez González, Enrique and Vielva Martínez, Patricio},
}