Studying the dynamical and thermal structure of the hot gaseous component in galaxy clusters by means of unprecedentedly detailed synthetic observations of advanced cosmological, hydrodynamical simulations

• Applicant: Professor Dr. Klaus Dolag
• Subject Area: Astrophysics and Astronomy
• Term: from 2012 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 223765867

Being the largest gravitationally-bound objects in the Universe, clusters can be treated as cosmological probes to constrain the underlying cosmological model. Additionally, they also represent optimal laboratories to study the baryonic physics and its interplay with structure formation.Especially when observed in at X-ray wavelength, the hot, diffuse intracluster gas (ICM) filling their potential well allows us to infer valuable information on the intrinsic structure, dynamical and evolutionary status, as well as on the thermal and chemical properties of the ICM itself. Future X-ray missions, such as ASTRO-H and ATHENA, are expected to provide very detailed insights into the properties of the ICM, with a very high precision in X-ray spectroscopy not yet reached so far. Moreover, the X-ray eROSITA all-sky survey and the follow-up missions of various current and ongoing surveys (like SPT, DES, EUCLID, etc.), will provide us with vast catalogs of X-ray detected clusters, increasing enormously the statistics for studies on scaling relations and cosmic evolution, and for cluster-based cosmological investigations.To keep the pace with observational improvements, virtual observations of numerical hydro-simulations are required, which are able to simulate very large cosmic volumes with a variety of physical processes describing the baryonic component. This will enable us to pursue forefront studies on large-scale structures and galaxy clusters, with a so-far unaccomplished accuracy. With special attention for X-ray observations, we will employ a novel X-ray photon simulator, PHOX, capable to efficiently generate synthetic observations from both huge and high-resolution simulation outputs. By means of this tool, in particular, we propose here to investigate the X-ray emission from simulated galaxy clusters, in order to deeply study the velocity field and thermo-dynamical structure of the ICM and make predictions on the detectability of these properties with the up-coming X-ray missions. This will permit, for instance, to constrain the scatter of scaling relations, study the covariance between X-ray observables and investigate the effects of Dark Energy cosmologies on the estimation of cluster global properties.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Hans Böhringer