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

The main goal of this work is to compare the results of three dynamical massestimators to the X-ray hydrostatic values, focussing on massive galaxyclusters at intermediate redshifts $z\sim0.3$. We estimated dynamical masseswith the virial theorem, the Jeans equation, and the caustic method usingwide-field VIMOS spectroscopy. We investigated the role of colour selection andthe impact of substructures on the dynamical estimators. The Jeans and causticmethods give consistent results, whereas the virial theorem leads to masses$\sim15\%$ larger. The Jeans, caustic, and virial masses are respectively$\sim20\%$, $\sim30\%$, and $\sim50\%$ larger than the hydrostatic values.Large scatters of $\gtrsim50\%$ are mainly due to the two outliers RXCJ0014 andRXCJ1347; excluding the latter increases the mass ratios by $\sim10\%$, givinga fractional mass bias significant at $\gtrsim2\sigma$. We found a correlationbetween the dynamical-to-hydrostatic mass ratio and two substructureindicators, suggesting a bias in the dynamical measurements. The velocitydispersions of blue galaxies are $\sim15\%$ ($\sim25\%$ after removing thesubstructures) larger than that of the red-sequence galaxies; using the latterleads to dynamical masses $\sim10\%-15\%$ smaller. Discarding the galaxies partof substructures reduces the masses by $\sim15\%$; the effect is larger for themore massive clusters, owing to a higher level of substructures. After thesubstructure analysis, the dynamical masses are in perfect agreement with thehydrostatic values and the scatters around the mean ratios are divided by$\sim2$.

Comparison of hydrostatic and dynamical masses of distant X-ray luminous galaxy clusters