MultiDark-Clusters: Galaxy Cluster Mock Light-Cones, eROSITA and the
  Cluster Power Spectrum
  Cosmological simulations are fundamental tools to study structure formation
and the astrophysics of evolving structures, in particular clusters of
galaxies. While hydrodynamical simulations cannot sample efficiently large
volumes and explore different cosmologies at the same time, N-body simulations
lack the baryonic physics that is crucial to determine the observed properties
of clusters. One solution is to use (semi-)analytical models to implement the
needed baryonic physics. In this way, we can generate the many mock universes
that will be required to fully exploit future large sky surveys, such as that
from the upcoming eROSITA X-ray telescope. We developed a phenomenological
model based on observations of clusters to implement gas density and
temperature information on the dark-matter-only halos of the MultiDark
simulations. We generate several full-sky mock light-cones of clusters for the
WMAP and Planck cosmologies, adopting different parameters in our
phenomenological model of the intra-cluster medium. For one of these
simulations and models, we also generate 100 light-cones corresponding to 100
random observers and explore the variance among them in several quantities. In
this first paper on MultiDark mock galaxy cluster light-cones, we focus on
presenting our methodology and discuss predictions for eROSITA, in particular,
exploring the potential of angular power spectrum analyses of its detected (and
undetected) cluster population to study X-ray scaling relations, the
intra-cluster medium, and the composition of the cosmic X-ray background. We
make publicly available on-line more than 400 GB of light-cones, which include
the expected eROSITA count rate, on Skies & Universes
(http://www.skiesanduniverses.org).
