SIBELIUS-DARK: a galaxy catalogue of the local volume from a constrained realization simulation
Stuart McAlpine, John Helly, Matthieu Schaller, Till Sawala, Guilhem Lavaux, Jens Jasche, Carlos S. Frenk, Adrian Jenkins, J. R. Lucey, Peter H. Johansson
Abstract
ABSTRACT We present sibelius-dark, a constrained realization simulation of the local volume to a distance of 200 Mpc from the Milky Way. sibelius-dark is the first study of the ‘Simulations Beyond The Local Universe’ (sibelius) project, which has the goal of embedding a model Local Group-like system within the correct cosmic environment. The simulation is dark-matter-only, with the galaxy population calculated using the semi-analytic model of galaxy formation, galform. We demonstrate that the large-scale structure that emerges from the sibelius constrained initial conditions matches well the observational data. The inferred galaxy population of sibelius-dark also match well the observational data, both statistically for the whole volume and on an object-by-object basis for the most massive clusters. For example, the K-band number counts across the whole sky, and when divided between the northern and southern Galactic hemispheres, are well reproduced by sibelius-dark. We find that the local volume is somewhat unusual in the wider context of ΛCDM: it contains an abnormally high number of supermassive clusters, as well as an overall large-scale underdensity at the level of ≈5 per cent relative to the cosmic mean. However, whilst rare, the extent of these peculiarities does not significantly challenge the ΛCDM model. sibelius-dark is the most comprehensive constrained realization simulation of the local volume to date, and with this paper we publicly release the halo and galaxy catalogues at z = 0, which we hope will be useful to the wider astronomy community.