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Department of Physics

# Staff profile

## Publication details for Prof Richard Massey

Merten, J., Meneghetti, M., Postman, M., Umetsu, K., Zitrin, A., Medezinski, E., Nonino, M., Koekemoer, A., Melchior, P., Gruen, D., Moustakas, L.A., Bartelmann, M., Host, O., Donahue, M., Coe, D., Molino, A., Jouvel, S., Monna, A., Seitz, S., Czakon, N., Lemze, D., Sayers, J., Balestra, I., Rosati, P., Benítez, N., Biviano, A., Bouwens, R., Bradley, L., Broadhurst, T., Carrasco, M., Ford, H., Grillo, C., Infante, L., Kelson, D., Lahav, O., Massey, R., Moustakas, J., Rasia, E., Rhodes, J., Vega, J. & Zheng, W. (2015). CLASH: The Concentration-Mass Relation of Galaxy Clusters. Astrophysical journal 806(1): 4.

### Abstract

We present a new determination of the concentration–mass (c–M) relation for galaxy clusters based on our comprehensive lensing analysis of 19 X-ray selected galaxy clusters from the Cluster Lensing and Supernova Survey with Hubble (CLASH). Our sample spans a redshift range between 0.19 and 0.89. We combine weak-lensing constraints from the Hubble Space Telescope (HST) and from ground-based wide-field data with strong lensing constraints from HST. The results are reconstructions of the surface-mass density for all CLASH clusters on multi-scale grids. Our derivation of Navarro–Frenk–White parameters yields virial masses between $0.53\times {{10}^{15}}\;{{M}_{\odot }}/h$ and $1.76\times {{10}^{15}}\;{{M}_{\odot }}/h$ and the halo concentrations are distributed around ${{c}_{200c}}\sim 3.7$ with a $1\sigma$ significant negative slope with cluster mass. We find an excellent 4% agreement in the median ratio of our measured concentrations for each cluster and the respective expectation from numerical simulations after accounting for the CLASH selection function based on X-ray morphology. The simulations are analyzed in two dimensions to account for possible biases in the lensing reconstructions due to projection effects. The theoretical c–M relation from our X-ray selected set of simulated clusters and the c–M relation derived directly from the CLASH data agree at the 90% confidence level.