THE THREE HUNDRED project, which has 324 large galaxy clusters modelled with different full-physics hydrodynamical re-simulations and semi-analytical models (SAMs), is aiming to provide a large catalogue of theoretically modelled galaxy clusters for cosmological and astrophysical applications.

These re-simulation regions are selected from the Multi-Dark Planck 2 simulation. It uses ginnungagap to reproduce the zoom-in ICs, which have large (15 Mpc/h in radius) high-resolution regions for the clusters located in the centre. Currently, it has Gadget-MUSIC and Gadget-X (more hydro-simulation codes results are coming) run over, along with three SAMs (Galacticus, SAG and SAGE).

--- A short description of the publications ---

In the introduction paper (Cui et al. 2018), we present the data set and study the differences to observations for fundamental galaxy cluster properties and scaling relations. We find that the modelled galaxy clusters are generally in reasonable agreement with observations with respect to baryonic fractions and gas scaling relations at redshift z = 0. However, there are still some (model-dependent) differences, such as central galaxies being too massive, and galaxy colours (g - r) being bluer (about 0.2 dex lower at the peak position) than in observations. The agreement in gas scaling relations down to 10^{13} h^{-1} M_{sun} between the simulations indicates that particulars of the sub-grid modelling of the baryonic physics only has a weak influence on these relations. We also include - where appropriate - a comparison to three semi-analytical galaxy formation models as applied to the same underlying dark-matter-only simulation. All simulations and derived data products are publicly available.

In the “The Influence of Environment on Simulated Galaxy Properties” paper (Wang et al. 2018), we use galaxy samples from hydrodynamical re-simulations to examine the relationship between galaxy properties (specific star formation rate (sSFR), fraction of star-forming galaxies, g - r color, and overdensity sigma_1) and environments (clusters, cluster vicinity and field regions). We found that overdensity is the primary drive for the changes of the galaxy properties, which is simply because the overdensity is correlated with the galaxy masses; at fixed overdensity, a galaxy’s color is also independent of whether it lives within a cluster or within the field.

In the “The evolution of galaxy cluster density profiles” paper (Mostoghiu et al. 2018), we only focused on the central cluster sample (or the mass-complete sample, 324 clusters in total) and studied their radial mass density profiles and evolutions. By tracking the progenitors of the clusters at z = 0, we found that their median shape (both gas and total profiles) is already in place by z = 2.5. However, selecting a dynamically relaxed subsample, we observed a shift of the scale radius r_s towards larger values at earlier times. Classifying the whole sample by formation time, this evolution is understood as a result of a two-phase halo mass accretion process. Early-forming clusters - identified as relaxed today - have already entered their slow accretion phase, hence their mass growth occurs mostly at the outskirts. Late-forming clusters - which are still unrelaxed today - are in their fast accretion phase, thus the central region of the clusters is still growing.

In the “ram pressure and gas content of haloes and subhaloes in the phase-space plane” paper (Arthur et al. 2019), we investigate (i) how the gas content of the surrounding haloes correlates with the phase-space position at z = 0 and (ii) the role that ram pressure plays in this correlation. We show that the halo gas content is tightly correlated with the phase-space position. At ~1.5-2 {R}_{200} of the cluster dark matter halo, we find an extremely steep decline in the halo gas content of infalling haloes and subhaloes irrespective of cluster mass, possibly indicating the presence of an accretion shock. We also find that subhaloes are particularly gas-poor, even in the cluster outskirts, which could indicate active regions of ongoing pre-processing. By modelling the instantaneous ram pressure experienced by each halo and subhalo at z = 0, we show that the ram pressure intensity is also well correlated with the phase-space position, which is again irrespective of cluster mass. In fact, we show that regions in the phase-space plane with high differential velocity between a halo or subhalo and its local gas environment are almost mutually exclusive with high halo gas content regions. This suggests a causal link between the gas content of objects and the instantaneous ram pressure they experience, where the dominant factor is the differential velocity.

--- Workshops ---

Informations about the first (Crystal Clear Clusters) workshop for this project:

Informations about the second (Glenfiddling Galaxy clusters) workshop for this project:

--- Projects (restricted access) ---

Many works are listed at the pbworks page (require permission to access)