Pacaud, F.F.PacaudPierre, M.M.PierreMelin, J. -B.J. -B.MelinAdami, C.C.AdamiEvrard, A. E.A. E.EvrardGalli, S.S.GalliGASTALDELLO, FABIOFABIOGASTALDELLOMaughan, B. J.B. J.MaughanSereno, MauroMauroSerenoAlis, S.S.AlisAltieri, B.B.AltieriBirkinshaw, M.M.BirkinshawCHIAPPETTI, LUCIOLUCIOCHIAPPETTIFaccioli, L.L.FaccioliGiles, P. A.P. A.GilesHorellou, C.C.HorellouIOVINO, AngelaAngelaIOVINOKoulouridis, E.E.KoulouridisLe Fèvre, J. -P.J. -P.Le FèvreLidman, C.C.LidmanLieu, M.M.LieuMaurogordato, S.S.MaurogordatoMoscardini, L.L.MoscardiniPlionis, M.M.PlionisPOGGIANTI, Bianca MariaBianca MariaPOGGIANTIPompei, E.E.PompeiSadibekova, T.T.SadibekovaValtchanov, I.I.ValtchanovWillis, J. P.J. P.Willis2020-11-122020-11-1220180004-6361http://hdl.handle.net/20.500.12386/28299Context. We present an estimation of cosmological parameters with clusters of galaxies. <BR /> Aims: We constrain the Ω<SUB>m</SUB>, σ<SUB>8</SUB>, and w parameters from a stand-alone sample of X-ray clusters detected in the 50 deg<SUP>2</SUP> XMM-XXL survey with a well-defined selection function. <BR /> Methods: We analyse the redshift distribution of a sample comprising 178 high signal-to-noise ratio clusters out to a redshift of unity. The cluster sample scaling relations are determined in a self-consistent manner. <BR /> Results: In a lambda cold dark matter (ΛCDM) model, the cosmology favoured by the XXL clusters compares well with results derived from the Planck Sunyaev-Zel'dovich clusters for a totally different sample (mass/redshift range, selection biases, and scaling relations). However, with this preliminary sample and current mass calibration uncertainty, we find no inconsistency with the Planck CMB cosmology. If we relax the w parameter, the Planck CMB uncertainties increase by a factor of 10 and become comparable with those from XXL clusters. Combining the two probes allows us to put constraints on Ω<SUB>m</SUB> = 0.316 ± 0.060, σ<SUB>8</SUB> = 0.814 ± 0.054, and w = -1.02 ± 0.20. <BR /> Conclusions: This first self-consistent cosmological analysis of a sample of serendipitous XMM clusters already provides interesting insights into the constraining power of the XXL survey. Subsequent analysis will use a larger sample extending to lower confidence detections and include additional observable information, potentially improving posterior uncertainties by roughly a factor of 3. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA.STAMPAenArticle10.1051/0004-6361/2018340222-s2.0-85057331959000450930100010https://www.aanda.org/articles/aa/abs/2018/12/aa34022-18/aa34022-18.html2018A&A...620A..10PFIS/05 - ASTRONOMIA E ASTROFISICAScienze Fisiche Settori ERC (ERC) di riferimento::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation