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 Plus annual

Presents the access of premium content as premium feature

Premium Content

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 annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

If properly calibrated, the shapes of galaxy clusters can be used toinvestigate many physical processes: from feedback and quenching of starformation, to the nature of dark matter. Theorists frequently measure shapesusing moments of inertia of simulated particles'. We instead create mock(optical, X-ray, strong- and weak-lensing) observations of the twenty-two mostmassive ($\sim10^{14.7}\,M_\odot$) relaxed clusters in the BAHAMAS simulations.We find that observable measures of shape are rounder. Even when moments ofinertia are projected into 2D and evaluated at matched radius, theyoverestimate ellipticity by 56\% (compared to observable strong lensing) and430\% (compared to observable weak lensing). Therefore, we propose matchablequantities and test them using observations of eight relaxed clusters from the{\emph Hubble Space Telescope} and {\emph Chandra X-Ray Observatory}. We alsorelease our HST data reduction and lensing analysis software to the community.In real clusters, the ellipticity and orientation angle at all radii arestrongly correlated. In simulated clusters, the ellipticity of inner($<r_{\mathrm{vir}}/20$) regions becomes decoupled: for example with greatermisalignment of the central cluster galaxy. This may indicate overly efficientimplementation of feedback from active galactic nuclei. Future exploitation ofcluster shapes as a function of radii will require better understanding of corebaryonic processes. Exploitation of shapes on any scale will requirecalibration on simulations extended all the way to mock observations.

Reconciling galaxy cluster shapes, measured by theorists vs observers