Debiased Galaxy Cluster Pressure Profiles from X-Ray Observations and Simulations

We present an updated model for the average cluster pressure profile, adjusted for hydrostatic mass bias by combining results from X-ray observations with cosmological simulations. Our model estimates this bias by fitting a power law to the relation between the true halo mass and X-ray cluster mass in hydrodynamic simulations (IllustrisTNG, BAHAMAS, and MACSIS). As an example application, we consider the REXCESS X-ray cluster sample and the universal pressure profile derived from scaled and stacked pressure profiles. We find adjusted masses, M-500c, that are less than or similar to 15% higher and scaled pressures P/P-500c that have less than or similar to 35% lower normalization than previously inferred. Our debiased pressure profile (DPP) is well-fit by a generalized Navarro-Frenk-White function, with parameters [P-0, c(500), alpha, beta, gamma] = [5.048, 1.217, 1.192, 5.490, 0.433] and does not require a mass-dependent correction term. When the DPP is used to model the Sunyaev-Zel'dovich (SZ) effect, we find that the integrated Compton Y-M relation has only minor deviations from self-similar scaling. The thermal SZ angular power spectrum is lower in amplitude by approximately 30%, assuming nominal cosmological parameters (e.g., omega(m) = 0.3, sigma(8) = 0.8), and is broadly consistent with recent Planck results without requiring additional bias corrections.

Automated summary

An updated model for average cluster pressure profile has been proposed, incorporating results from X-ray observations and cosmological simulations to correct hydrostatic mass bias. Analysis of existing data using this model reveals adjustments to previously inferred values for cluster masses and pressures.