Published Article: Distinct distributions of elliptical and disk galaxies across the Local Supercluster as a ΛCDM prediction
In this article published in Nature Astronomy, we use the SIBELIUS DARK constrained simulation to study the distribution of the brightest ellipticals and the brightest disk galaxies in the Local Universe and show that the distribution of these bright galaxies are in accordance with the predictions of the standard Lambda Cold Dark Matter (ΛCDM) model.
Abstract: Galaxies of different types are not equally distributed in the Local Universe. In particular, the supergalactic plane is prominent among the brightest ellipticals, but inconspicuous among the brightest disk galaxies. This striking difference provides a unique test for our understanding of galaxy and structure formation. Here we use the SIBELIUS DARK constrained simulation to confront the predictions of the standard Lambda Cold Dark Matter (ΛCDM) model and standard galaxy formation theory with these observations. We find that SIBELIUS DARK reproduces the spatial distributions of disks and ellipticals and, in particular, the observed excess of massive ellipticals near the supergalactic equator. We show that this follows directly from the local large-scale structure and from the standard galaxy formation paradigm, wherein disk galaxies evolve mostly in isolation, while giant ellipticals congregate in the massive clusters that define the supergalactic plane. Rather than being anomalous as earlier works have suggested, the distributions of giant ellipticals and disks in the Local Universe and in relation to the supergalactic plane are key predictions of the ΛCDM model.