The connection between massive galaxies and their dark matter haloes from z = 0.25 to z ∼ 4 from the combined COSMOS, XMM-LSS and ECDF-S fields

Understanding how galaxies populate and grow within dark matter haloes is essential for linking the observed evolution of galaxies to the hierarchical growth of structure. We present a galaxy clustering analysis using optical and near-infrared data from the UltraVISTA and VIDEO surveys covering 9.3 deg2 across the COSMOS, XMM-LSS and ECDF-S fields, ∼5 × larger than previous comparable studies, providing sufficient volume to determine the halo occupation of the most massive galaxies to z ∼ 4. We measure the angular two-point correlation function for stellar-mass-selected galaxies over 0.25 < z < 4 and by combining the three fields, we reduce the cosmic variance by a factor of ∼2 compared to the individual fields. The stellar-to-halo mass ratio peaks at a halo mass of Mh ≈ 1012 M⊙ and is a maximum at z ∼ 1. For the most massive galaxies, the peak halo mass (Mₕᵖᵉᵃᵏ) increases from z = 1 → 0, while the peak stellar mass in such haloes remains approximately constant, indicating that at z < 1 massive galaxy formation becomes less efficient. We also find a steady increase in the satellite fraction since z ∼ 1, from which we infer that massive halos continue to grow hierarchically while their central galaxies experience suppressed stellar-mass growth. We suggest this is due to the central massive galaxies having their growth controlled by feedback from active galactic nuclei feedback, likely from low-power stochastic radio emission.