In this paper, we assess the impact of numerical resolution and of theimplementation of energy input from AGN feedback models on the inner structureof cluster sub-haloes in hydrodynamic simulations. We compare several zoom-inre-simulations of a sub-sample of the cluster-sized haloes studied inMeneghetti et al. (2020), obtained by varying mass resolution, softening lengthand AGN energy feedback scheme. We study the impact of these different setupson the subhalo abundances, their radial distribution, their density and massprofiles and the relation between the maximum circular velocity, which is aproxy for subhalo compactness. Regardless of the adopted numerical resolutionand feedback model, subhaloes with masses Msub < 1e11Msun/h, the most relevantmass-range for galaxy-galaxy strong lensing, have maximum circular velocities~30% smaller than those measured from strong lensing observations of Bergaminiet al. (2019). We also find that simulations with less effective AGN energyfeedback produce massive subhaloes (Msub>1e11 Msun/h ) with higher maximumcircular velocity and that their Vmax - Msub relation approaches the observedone. However the stellar-mass number count of these objects exceeds the onefound in observations and we find that the compactness of these simulatedsubhaloes is the result of an extremely over-efficient star formation in theircores, also leading to larger-than-observed subhalo stellar mass. We concludethat simulations are unable to simultaneously reproduce the observed stellarmasses and compactness (or maximum circular velocities) of cluster galaxies.Thus, the discrepancy between theory and observations that emerged from theanalysis of Meneghetti et al. (2020) persists. It remains an open question asto whether such a discrepancy reflects limitations of the currentimplementation of galaxy formation models or the LCDM paradigm.
Galaxies in the central regions of simulated galaxy clusters
MERCURIO AMATA;
2022-01-01
Abstract
In this paper, we assess the impact of numerical resolution and of theimplementation of energy input from AGN feedback models on the inner structureof cluster sub-haloes in hydrodynamic simulations. We compare several zoom-inre-simulations of a sub-sample of the cluster-sized haloes studied inMeneghetti et al. (2020), obtained by varying mass resolution, softening lengthand AGN energy feedback scheme. We study the impact of these different setupson the subhalo abundances, their radial distribution, their density and massprofiles and the relation between the maximum circular velocity, which is aproxy for subhalo compactness. Regardless of the adopted numerical resolutionand feedback model, subhaloes with masses Msub < 1e11Msun/h, the most relevantmass-range for galaxy-galaxy strong lensing, have maximum circular velocities~30% smaller than those measured from strong lensing observations of Bergaminiet al. (2019). We also find that simulations with less effective AGN energyfeedback produce massive subhaloes (Msub>1e11 Msun/h ) with higher maximumcircular velocity and that their Vmax - Msub relation approaches the observedone. However the stellar-mass number count of these objects exceeds the onefound in observations and we find that the compactness of these simulatedsubhaloes is the result of an extremely over-efficient star formation in theircores, also leading to larger-than-observed subhalo stellar mass. We concludethat simulations are unable to simultaneously reproduce the observed stellarmasses and compactness (or maximum circular velocities) of cluster galaxies.Thus, the discrepancy between theory and observations that emerged from theanalysis of Meneghetti et al. (2020) persists. It remains an open question asto whether such a discrepancy reflects limitations of the currentimplementation of galaxy formation models or the LCDM paradigm.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
