Volume 617, September 2018
|Number of page(s)||15|
|Section||Cosmology (including clusters of galaxies)|
|Published online||18 September 2018|
Resolving the hydrostatic mass profiles of galaxy clusters at z ∼ 1 with XMM-Newton and Chandra
IRFU, CEA, Université Paris-Saclay, 91191 Gif-Sur-Yvette, France
2 Université Paris Diderot, AIM, Sorbonne Paris Cité, CEA, CNRS, 91191 Gif-sur-Yvette, France
Accepted: 7 May 2018
We present a detailed study of the integrated total hydrostatic mass profiles of the five most massive M500SZ < 5 × 1014 M⊙ galaxy clusters selected at z ∼ 1 via the Sunyaev–Zel’dovich effect. These objects represent an ideal laboratory to test structure formation models where the primary driver is gravity. Optimally exploiting spatially-resolved spectroscopic information from XMM-Newton and Chandra observations, we used both parametric (forward, backward) and non-parametric methods to recover the mass profiles, finding that the results are extremely robust when density and temperature measurements are both available. Our X-ray masses at R500 are higher than the weak lensing masses obtained from the Hubble Space Telescope (HST), with a mean ratio of 1.39−0.35+0.47. This offset goes in the opposite direction to that expected in a scenario where the hydrostatic method yields a biased, underestimated, mass. We investigated halo shape parameters such as sparsity and concentration, and compared to local X-ray selected clusters, finding hints for evolution in the central regions (or for selection effects). The total baryonic content is in agreement with the cosmic value at R500. Comparison with numerical simulations shows that the mass distribution and concentration are in line with expectations. These results illustrate the power of X-ray observations to probe the statistical properties of the gas and total mass profiles in this high mass, high-redshift regime.
Key words: X-rays: / galaxies: clusters – dark matter
© ESO 2018
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.