DARKSKIES: A suite of super-sampled zoom-in simulations of galaxy clusters with self-interacting dark matter

We present the ‘DARKSKIES’ suite of one hundred, zoom-in hydrodynamic simulations of massive (M200 > 5 × 1014 M⊙) galaxy clusters with self-interacting dark matter (SIDM). We super-sampled the simulations such that mDM/mgas ∼ 0.1, enabling us to simulate a dark matter particle mass of m = 0.68 × 108 M⊙ an order of magnitude faster, whilst exploring SIDM in the core of clusters at extremely high resolution. We calibrated the baryonic feedback to produce observationally consistent and realistic galaxy clusters across all simulations and simulated five models of velocity-independent SIDM targeting the expected sensitivity of future telescopes - σDM/m = 0.,0.01, 0.05, 0.1, 0.2 cm2/g. We find that the density profiles exhibit the characteristic core even in the smallest of cross-sections, with cores developing only at late times (z < 0.5). We investigated the dynamics of the brightest cluster galaxy (BCG) inside the dark matter halo and find that in SIDM cosmologies there exists a so-called wobbling not observed in collisionless dark matter. We find that this wobble is driven by mass accreting onto a cored density profile with the signal peaking at z = 0.25 and dropping thereafter. This finding is further supported by the existence of an anti-correlation between the offset between the BCG and the dark matter halo and its relative velocity in SIDM only, a hallmark of harmonic oscillation.