A high coverage view of the thermodynamics and metal abundance in the outskirts of the nearby galaxy cluster Abell 2199

TL;DR

This study combines Suzaku and XMM-Newton data to analyze the outskirts of galaxy cluster Abell 2199, revealing entropy profiles consistent with gravitational models and uniform metal enrichment, with notable azimuthal variations.

Contribution

It provides the first comprehensive azimuthal analysis of the cluster outskirts, correcting for gas clumping and measuring entropy and metal distribution.

Findings

Entropy profile follows a power law with a slope of 1.20 ± 0.23.

Gas mass fraction aligns with cosmic baryon fraction.

Metallicity is uniform at about 0.29 Z_solar across directions.

Abstract

We present a joint Suzaku and XMM-Newton analysis of the outskirts of the nearby galaxy cluster Abell 2199, the only nearby galaxy cluster to be observed with near complete azimuthal coverage with Suzaku. Using the XMM-Newton observations to correct for the effects of gas clumping, we find that the azimuthally averaged entropy profile in the outskirts follows a power law with a slope of $1.20 \pm 0.23$, statistically consistent with a slope of 1.1 predicted by non-radiative simulations for purely gravitational hierarchical structure formation. However, when divided into 10 sectors, the entropy shows significant azimuthal variation, with some sectors lying below the baseline level. The azimuthally averaged gas mass fraction is found to agree with the cosmic mean baryon fraction. The metal abundance in the outskirts is found to be consistent with being uniform in all directions and it has an average value of $0.29_{-0.03}^{+0.03}\,Z_{\odot}$, consistent with the gas accreting onto clusters being pre-enriched with metals.