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

We probe the dynamical mass profiles of 10 galaxy clusters from the HIghestX-ray FLUx Galaxy Cluster Sample (HIFLUGCS) using galaxy kinematics. Wenumerically solve the spherical Jeans equation, and parameterize the dynamicalmass profile and the galaxy velocity anisotropy profile using two generalfunctions to ensure that our results are not biased towards any specific model.The mass-velocity anisotropy degeneracy is ameliorated by using two "virialshape parameters" that depend on the fourth moment of velocity distribution.The resulting velocity anisotropy estimates consistently show a nearlyisotropic distribution in the inner regions, with an increasing radialanisotropy towards large radii. We compare our derived dynamical masses withthose calculated from X-ray gas data assuming hydrostatic equilibrium, findingthat massive and rich relaxed clusters generally present consistent massmeasurements, while unrelaxed or low-richness clusters have systematicallylarger total mass than hydrostatic mass by an average of 50\%. This might helpalleviate current tensions in the measurement of $\sigma_8$, but it also leadsto cluster baryon fractions below the cosmic value. Finally, our approachprobes accelerations as low as $10^{-11}$ m s$^{-2}$, comparable to theoutskirts of individual late-type galaxies. We confirm that galaxy clustersdeviate from the radial acceleration relation defined by galaxies.

Measuring galaxy cluster mass profiles into the low acceleration regime with galaxy kinematics