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

[Abridged] We present an analysis of the relation between the masses ofcluster- and group-sized halos, extracted from $\Lambda$CDM cosmological N-bodyand hydrodynamic simulations, and their velocity dispersions, at differentredshifts from $z=2$ to $z=0$. The main aim of this analysis is to understandhow the implementation of baryonic physics in simulations affects suchrelation, i.e. to what extent the use of the velocity dispersion as a proxy forcluster mass determination is hampered by the imperfect knowledge of thebaryonic physics. In our analysis we use several sets of simulations withdifferent physics implemented. Velocity dispersions are determined using threedifferent tracers, DM particles, subhalos, and galaxies.  We confirm that DM particles trace a relation that is fully consistent withthe theoretical expectations based on the virial theorem and with previousresults presented in the literature. On the other hand, subhalos and galaxiestrace steeper relations, and with larger values of the normalization. Suchrelations imply that galaxies and subhalos have a $\sim10$ per cent velocitybias relative to the DM particles, which can be either positive or negative,depending on halo mass, redshift and physics implemented in the simulation.  We explain these differences as due to dynamical processes, namely dynamicalfriction and tidal disruption, acting on substructures and galaxies, but not onDM particles. These processes appear to be more or less effective, depending onthe halo masses and the importance of baryon cooling, and may create anon-trivial dependence of the velocity bias and the $\soneD$--$\Mtwo$ relationon the tracer, the halo mass and its redshift.  These results are relevant in view of the application of velocity dispersionas a proxy for cluster masses in ongoing and future large redshift surveys.

The relation between velocity dispersion and mass in simulated clusters of galaxies: dependence on the tracer and the baryonic physics