The Evolution and Mass Dependence of Galaxy Cluster Pressure Profiles at 0.05 $\le z \le$ 0.60 and $4 \times 10^{14}$ M$_{\odot}$ $\le \textrm{M}_{500} \le 30 \times 10^{14}$ M$_{\odot}$

Abstract

We have combined X-ray observations from Chandra with Sunyaev-Zel'dovich (SZ) effect data from Planck and Bolocam to measure intra-cluster medium pressure profiles from 0.03R 500 ≤ R ≤ 5R 500 for a sample of 21 low-z galaxy clusters with a median redshift z = 0.08 and a median mass M 500 = 6.1 × 10 14 M and a sample of 19 mid-z galaxy clusters with z = 0.50 and M 500 = 10.6 × 10 14 M . The mean scaled pressure in the low-z sample is lower at small radii and higher at large radii, a trend that is accurately reproduced in similarly selected samples from The Three Hundred simulations. This difference appears to be primarily due to dynamical state at small radii, evolution at intermediate radii, and a combination of evolution and mass dependence at large radii. Furthermore, the overall flattening of the mean scaled pressure profile in the low-z sample compared to the mid-z sample is consistent with expectations due to differences in mass accretion rate and the fractional impact of feedback mechanisms. In agreement with previous studies, the fractional scatter about the mean scaled pressure profile reaches a minimum of 20 per cent near 0.5R 500 . This scatter is consistent between the low-z and mid-z samples at all radii, suggesting it is not strongly impacted by sample selection, and this general behavior is reproduced in The Three Hundred simulations. Finally, analytic functions that approximately describe the mass and redshift trends in mean pressure profile shape are provided.

panco2: a Python library to measure intracluster medium pressure profiles from Sunyaev-Zeldovich observations

“…In particular, the very selfconstrained shape of the functional form of the profile and the important correlations in the parameter space make model fitting complex, and the recovered parameter values hard to interpret (see e.g. Nagai et al 2007;Battaglia et al 2012;Sayers et al 2022).…”

“…Romero et al 2017Romero et al , 2020, Bolocam (e.g. Sayers et al 2022), or ALMA (e.g. Di Mascolo et al 2019).…”

“…For example, the rewriting of the gNFW model from Battaglia et al (2012) (see also e.g. Sayers et al 2022) offers a way to constrain the same functional form, but minimizing the correlations in the parameter space. Even though it is still possible to use a radially-binned profile and to fit any other functional form on the pressure bins a posteriori (see e.g.…”

“…In particular, high angular resolution millimeter observations of clusters with large aperture telescopes have successfully been used to measure cluster pressure profiles, and are today one of the preferred sources of data for studies of the mean pressure profile of clusters (e.g. Pointecouteau et al 2021;Sayers et al 2022;Young et al in prep. ).…”

i(cm)z, a semi-analytic model for the thermodynamic properties in galaxy clusters: Calibrations with mass and redshift, and implication for the hydrostatic bias

“…with P 500 = 1.65 × 10 −3 M 500 /3 × 10 14 h −1 70 M ⊙ 2/3+α M keV cm −3 E 8/3 z h 2 70 and P r = P 0 (c 500 x) −γ [1 + (c 500 x) α ] (β−γ)/α with x = r/R 500 , the parameters (P 0 , c 500 , γ, α, β) equal to (8.403, 1.177, 0.308, 1.051, 5.491), and α M = 0.12, accounting for the observed deviation from the standard self-similar scaling, set as in Arnaud et al (2010) (alternative values for the same model or different models are available in, e.g., Planck Collaboration et al 2013;Ghirardini et al 2019a,b;Sayers et al 2022);…”