Multi-probe analysis of the galaxy cluster CL J1226.9+3332: hydrostatic mass and hydrostatic-to-lensing bias

TL;DR

This study combines multi-wavelength observations of a high-redshift galaxy cluster to compare hydrostatic and lensing mass estimates, assessing biases and systematic uncertainties in mass measurements.

Contribution

It demonstrates a multi-probe approach integrating SZ, X-ray, and lensing data to evaluate hydrostatic-to-lensing mass bias in galaxy clusters.

Findings

Hydrostatic mass estimate: (7.65 +- 1.03) x 10^14 Msun

Lensing mass estimate: (7.35 +- 0.65) x 10^14 Msun

Hydrostatic-to-lensing bias is consistent with zero within 20%

Abstract

We present a multi-probe analysis of the well-known galaxy cluster CL J1226.9+3332 as a proof of concept for multi-wavelength studies within the framework of the NIKA2 Sunyaev-Zeldovich Large Program (LPSZ). CL J1226.9+3332 is a massive and high redshift (z = 0.888) cluster that has already been observed at several wavelengths. A joint analysis of the thermal SZ (tSZ) effect at millimeter wavelength with the NIKA2 camera and in X-ray with the XMM-Newton satellite permits the reconstruction of the cluster thermodynamical properties and mass assuming hydrostatic equilibrium. We test the robustness of our mass estimates against different definitions of the data analysis transfer function. Using convergence maps reconstructed from the data of the CLASH program we obtain estimates of the lensing mass, which we compare to the estimated hydrostatic mass. This allows us to measure the hydrostatic-to-lensing mass bias and the associated systematic effects related to the NIKA2 measurement. We obtain M500HSE = (7.65 +- 1.03) 1014 Msun and M500lens = (7.35 +- 0.65) 1014 Msun, which implies a HSE-to-lensing bias consistent with 0 within 20 percent.