English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We use a statistical sample of galaxy clusters from a large cosmological$N$-body$+$hydrodynamics simulation to examine the relation between morphology,or shape, of the X-ray emitting intracluster medium (ICM) and the massaccretion history of the galaxy clusters. We find that the mass accretion rate(MAR) of a cluster is correlated with the ellipticity of the ICM. Thecorrelation is largely driven by material accreted in the last $\sim 4.5$~Gyr,indicating a characteristic time-scale for relaxation of cluster gas.Furthermore, we find that the ellipticity of the outer regions ($R\sim R_{\rm500c}$) of the ICM is correlated with the overall MAR of clusters, whileellipticity of the inner regions ($\lesssim 0.5 R_{\rm 500c}$) is sensitive torecent major mergers with mass ratios of $\geq 1:3$. Finally, we examine theimpact of variations in cluster mass accretion history on the X-rayobservable-mass scaling relations. We show that there is a {\it continuous\/}anti-correlation between the residuals in the $T_x-M$ relation and clusterMARs, within which merging and relaxed clusters occupy extremes of thedistribution rather than form two peaks in a bi-modal distribution, as wasoften assumed previously. Our results indicate the systematic uncertainties inthe X-ray observable-mass relations can be mitigated by using the informationencoded in the apparent ICM ellipticity.

Imprints of Mass Accretion History on the Shape of the Intracluster Medium and the $T_X-M$ Relation