Pressure profiles of distant Galaxy clusters with Planck-SPT data

Filippo Oppizzi,Hervé Bourdin,Federico De Luca,The Chex-Mate Collaboration ,Pasquale Mazzotta

doi:10.1051/epjconf/202225700035

Filippo Oppizzi, Hervé Bourdin + Show 3 more

Open Access

https://doi.org/10.1051/epjconf/202225700035

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Abstract

We present a full set of numerical tools to extract Galaxy Cluster pressure profiles from the joint analysis of Planck and South Pole Telescope (SPT) observations. Pressure profiles are powerful tracers of the thermodynamic properties and the internal structure of the clusters. Tracing the pressure over the cosmic times allows one to constraints the evolution of the cluster structure and the contribution of astrophysical phenomena. SPT and Planck are complementary to constrain the cluster structure at various spatial scales. The SPT cluster catalogue counts 677 cluster candidates up to redshift 1.7, it is a nearly mass-limited sample, an ideal benchmark to test cluster evolution. We developed a pipeline to first separate the cluster signal from the background and foreground components and then jointly fit a parametric profile model on a combination of Planck and SPT data. We validate our algorithm on a subsample of six clusters, common to the SPT and the CHEX-MATE catalogues, comparing the results with the profiles obtained from X-ray observations with XMM-Newton.

Highlights

Galaxy clusters form from the largest gravitational overdensities in the density field and track the evolution of the Universe at the largest scales [1]
We focus on the modelling of the Cosmic Microwave Background (CMB) signal using a linear combination (LC) of the three South Pole Telescope (SPT) channels and the 217 GHz channel of Planck that we re-project on a map with the same characteristic than the SPT ones
We compare the pressure profile derived from the Sunyaev-Zeldovich e↵ect (SZ) maps with the expectations from X-ray observations

Summary

Introduction

Galaxy clusters form from the largest gravitational overdensities in the density field and track the evolution of the Universe at the largest scales [1]. The intra-cluster gas pressure is a sensitive tracer of the internal structure of galaxy clusters. The Sunyaev-Zeldovich e↵ect (SZ) arises from the interaction of the free electrons in the ionised gas with the Cosmic Microwave Background (CMB) photons. It is a direct tracer of the gas pressure and is independent of the redshift. The gas emits bremsstrahlung radiation in X-ray, providing a complementary probe of the cluster structure that is sensitive to di↵erent density regimes. The high sensitivity of Planck and the SPT high resolution make the two instruments complementary in constraining the cluster structure over a wide range of scales.

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