the Cluster HEritage project with XMM-Newton

Mass Assembly and Thermodynamics at the Endpoint of structure formation

The Heritage program for the ESA’s X-ray satellite XMM-Newton has been activated for the first time in the AO-17. It has registered a large response from the community, with an oversubscription factor of 10, and has assigned about 3 Msec of XMM exposure time to two only projects, one led by our group . The X-ray observations will start in Spring 2018 and will be executed in the next 3 years. Our project is focused on the ultimate products of structure formation in mass and time: a large, unbiased, signal-to-noise limited sample of 118 galaxy clusters detected by Planck via their Sunyaev-Zel’dovich effect. Completing the high-fidelity XMM coverage of this sample has extraordinary legacy value. We will (i) obtain an accurate vision of the statistical properties of the local cluster population, and in the highest mass regime; (ii) uncover the provenance of non-gravitational heating; (iii) measure how their gas is shaped by the collapse into dark matter haloes and the mergers that built today’s clusters; (iv) resolve the major uncertainties in mass determinations that limit cosmological inferences; (v) build the foundation for cluster science with next-generation surveys.

With the preparation of Paper 1 (see below), we introduce the acronym for our project: CHEX-MATE, the Cluster HEritage project with XMM-Newton - Mass Assembly and Thermodynamics at the Endpoint of structure formation.


  • (February 2021): Paper 1: Programme Overview, accepted
  • (October 2020): Paper 1: Programme Overview, submitted
  • Science

    The sample includes 118 galaxy clusters selected to represent an unbiased census of
    Tier-1: the population of clusters at the most recent time (z < 0.2);
    Tier-2: the most massive objects to have formed thus far in the history of the Universe.

    Distribution of Tier-1 and Tier-2 objects

    The selection is based on the following criteria applied to the Planck-SZ2 catalog:
    Tier-1: SNR>6.5, z=[0.05, 0.2], DEC>0 ... 57 objects (43 to be observed)
    Tier-2: SNR>6.5, z<0.6, M500>7.25e14 ... 57 objects (37 to be observed)
    Tier-1 & Tier-2: 4 objects (0 to be observed)

    With this unique sample, our goals are to:
    • Assess the relative importance of gravitational and non-gravitational processes in shaping cluster properties
    • Probe the dynamical collapse of the gas on different scales
    • Construct a consistent picture of cluster mass estimates
    • Provide a unique reference for evolution studies and numerical modelling
    • Provide key inputs for the interpretation of upcoming surveys based on cluster baryon content
    • Establish a Legacy for Next Generation mission


    PI: M. Arnaud (CEA, Saclay, France); S. Ettori (INAF OAS, Bologna, Italy)

    Steering Committee: M. Arnaud, D. Eckert, S. Ettori, F. Gastaldello, R. Gavazzi, S. Kay, L. Lovisari, B. Maughan, E. Pointecouteau, G.W. Pratt, M. Rossetti, M. Sereno.

    WG X-ray (chair: Pratt & Rossetti)

    SC members; Bartalucci; Bourdin; De Grandi; Donahue; Duffy; Forman; Ghirardini; Ghizzardi; Iqbal Ahangar; Jones; Mazzotta; Molendi; Paltani; Sartoris; Schellenberger; Tozzi; Campitiello (PhD; ref. Ettori); De Luca (PhD; ref. Bourdin/Mazzotta)

    WG SZ (chair: Pointecouteau & Sayers)

    Aussel; Bartalucci; Bourdin; Burkutean; Clerc; De Petris; Gaspari; Macias; Mayet; Mazzotta; Melin; Mroczkowski; Oppizzi; Perotto; Streblyanska; Tarrio; Kéruzoré (PhD; ref. Mayet); Dupourqué (PhD; ref. Pointecouteau); De Luca (PhD; ref. Bourdin/Mazzotta); Kim (postdoc with Sayers)

    WG Lensing (chair: Gavazzi & Umetsu)

    Iqbal Ahangar; Jauzac; Meneghetti; Nonino; Okabe; Pires; Radovich; Sayers; Sereno

    WG Galaxies (chair: Maurogordato & Sereno)

    Barrena; Rubino-Martin; Aguado; Ferragamo; Streblyanska; Clerc; Cuillandre; Haines; Gavazzi; Nonino; Okabe; Radovich; Umetsu; van der Burg; Zarattini

    WG Hydrosymulations (chair: Kay & Rasia)

    Barnes; Borgani; Corasaniti; De Petris; Dolag; Gaspari; LeBrun; Salvati; Saro; Towler (PhD; ref. Kay); Yepes; Vazza

    WG Radio (chair: Bonafede & Cassano)

    Gitti; Iqbal Ahangar; Johnston-Hollitt; Vazza; Venturi


    List of 122 targets (118 clusters, plus 4 offset exposures), with priority for XMM observation (column "RPS"; 0 = data already available in the archive), requested exposure time (column "t_RPS" in ksec), and XMM revolution during which has been observed (column "REV"):





    (passwd needed)

    • Pbworks

      (archive of MASTER fits files, proposals, reports)
    • Slack

      (for on-going dicussion on e.g. X-ray pipelines, 1st year projects, general set-up)
    • Dropbox

      (as repository for massive files)