SIMBAD references

In this paper, we use two hydrodynamic simulations to study the barycentre offsets r_off between the entire halo and the gas or dark matter subhalo with largest overdensity. We restrict our analysis to those haloes with large rescaled offsets, i.e. r_off/r₂₀₀ >= 0.05. The haloes which are less massive and at higher redshifts are more likely to have larger r_off/r₂₀₀. The 3D velocity dispersion of the subhaloes with largest overdensity is found to have a similar mass and redshift dependence as r_off/r₂₀₀. We also find that the gas subhaloes with maximum overdensity and larger gas velocity dispersion σ_v^ ICM,sub^/σ₂₀₀ tend to have smaller barycentre offsets r_off/r₂₀₀. Similar result is found for the highest overdensity dark matter subhaloes but with less significance. This anticorrelation is more significant for the snapshot z = 0 than z = 0.2 and 0.5. The underlying physical mechanism for this anticorrelation remains to be explored.