Shape, spin and baryon fraction of clusters in the MareNostrum Universe

Abstract

The MareNostrum Universe is one of the largest cosmological SPH simulation done so far. It consists of $1024^3$ dark and $1024^3$ gas particles in a box of 500 $h^{-1}$ Mpc on a side. Here we study the shapes and spins of the dark matter and gas components of the 10,000 most massive objects extracted from the simulation as well as the gas fraction in those objects. We find that the shapes of objects tend to be prolate both in the dark matter and gas. There is a clear dependence of shape on halo mass, the more massive ones being less spherical than the less massive objects. The gas distribution is nevertheless much more spherical than the dark matter, although the triaxiality parameters of gas and dark matter differ only by a few percent and it increases with cluster mass. The spin parameters of gas and dark matter can be well fitted by a lognormal distribution function. On average, the spin of gas is 1.4 larger than the spin of dark matter. We find a similar behavior for the spins at higher redshifts, with a slightly decrease of the spin ratios to 1.16 at $z=1.$ The cosmic normalized baryon fraction in the entire cluster sample ranges from $Y_b=0.94$, at $z=1$ to $Y_b=0.92$ at $z=0$. At both redshifts we find a slightly, but statistically significant decrease of $Y_b$ with cluster mass.

7 pages, 6 figures. Accepted for publication in The Astrophysical Journal

References in corpus (5)

• The spin and shape of dark matter haloes in the Millennium simulation of a LambdaCDM universe
• The baryon fraction of LambdaCDM haloes
• Entropy of gas and dark matter in galaxy clusters
• Adiabatic scaling relations of galaxy clusters
• Dark and baryonic matter in the MareNostrum Universe

Cited by in corpus (27)

• Bimodal gas accretion in the Horizon-MareNostrum galaxy formation simulation
• The galaxy cluster mass scale and its impact on cosmological constraints from the cluster population
• Initial Conditions for Large Cosmological Simulations
• An algorithm to build mock galaxy catalogues using MICE simulations
• Angular momentum properties of haloes and their baryon content in the Illustris simulation
• Diffuse radio emission from clusters in the MareNostrum Universe simulation
• Exploring the Energetics of Intracluster Gas with a Simple and Accurate Model
• The distribution function of dark matter in massive haloes
• Cosmological Structure Formation under MOND: a new numerical solver for Poisson's equation
• The Effect of Gas Physics on the Halo Mass Function
• Exploring the hydrostatic mass bias in MUSIC clusters: application to the NIKA2 mock sample
• The dynamical structure of dark matter haloes
• Galaxy Zoo: Chiral correlation function of galaxy spins
• The strongest gravitational lenses: I. The statistical impact of cluster mergers
• Comparing galaxy formation in the L-GALAXIES semi-analytical model and the IllustrisTNG simulations
• Subhaloes gone Notts: Spin across subhaloes and finders
• Spin alignment of dark matter haloes in the shells of the largest voids
• On the relation between radial alignment of dark matter subhalos and host mass in cosmological simulations
• Probing the existence of a rich galaxy overdensity at z=5.2
• The flat density profiles of massive, and relaxed galaxy clusters
• Spatial Anisotropy of Galaxy Kinematics in Sloan Digital Sky Survey Galaxy Clusters
• Statistical properties of the linear tidal shear
• Simulations of structure formation in interacting dark energy cosmologies
• Kinematic effect in gravitational lensing by clusters of galaxies
• Haloes at the ragged edge: The importance of the splashback radius
• Spin transfer from dark matter to gas during halo formation
• Solving the puzzle of subhalo spins