Abstract
The eROSITA X-ray telescope on board the Spectrum-Roentgen-Gamma (SRG) mission will measure the position and properties of about 100,000 clusters of galaxies and 3 million active galactic nuclei over the full sky. To study the statistical properties of this ongoing survey, it is key to estimate the selection function accurately. We create a set of full sky light-cones using the MultiDark and UNIT dark matter only N-body simulations. We present a novel method to predict the X-ray emission of galaxy clusters. Given a set of dark matter halo properties (mass, redshift, ellipticity, offset parameter), we construct an X-ray emissivity profile and image for each halo in the light-cone. We follow the eROSITA scanning strategy to produce a list of X-ray photons on the full sky. We predict scaling relations for the model clusters, which are in good agreement with the literature. The predicted number density of clusters as a function of flux also agrees with previous measurements. Finally, we obtain a scatter of 0.21 (0.07, 0.25) for the X-ray luminosity -- mass (temperature -- mass, luminosity -- temperature) model scaling relations. We provide catalogues with the model photons emitted by clusters and active galactic nuclei. These catalogues will aid the eROSITA end to end simulation flow analysis and in particular the source detection process and cataloguing methods.
Highlights
As the most massive gravitationally bound objects in the Universe, Galaxy clusters have been widely used as probes for cosmology due to the exponential dependence of their abundance on cosmological parameters.The eROSITA X-ray telescope on board the SpectrumRoentgen-Gamma (SRG) mission will measure the position and properties of about 100 000 clusters of galaxies and 3 million active galactic nuclei over the full sky
Cosmological hydrodynamical simulations have been the keys for understanding the roles of cluster astrophysics (e.g. Springel et al 2001; Nagai et al 2007b; Le Brun et al 2014; Dolag et al 2016; Dubois et al 2016; McCarthy et al 2017; Barnes et al 2017a,b; Cui et al 2018; Pillepich et al 2018a; Henden et al 2018) and their impacts on the X-ray scaling relations (e.g. Kravtsov et al 2006; Planelles et al 2014), cool-core properties (e.g. Rasia et al 2015; Barnes et al 2018), cluster morphology (e.g. Green et al 2019; Cao et al 2020), hydrostatic mass bias (e.g. Rasia et al 2006; Nagai et al 2007a; Barnes et al 2020), AGN contamination of X-ray cluster signals (Biffi et al 2018) using detailed mock X-ray simulations
The scaling relations obtained are in good agreement with the literature (Lovisari et al 2015; Mantz et al 2016; Schellenberger & Reiprich 2017; Adami et al 2018; Bulbul et al 2019; Lovisari et al 2020; Sereno et al 2020; Umetsu et al 2020)
Summary
As the most massive gravitationally bound objects in the Universe, Galaxy clusters have been widely used as probes for cosmology due to the exponential dependence of their abundance on cosmological parameters (see Voit 2005; Allen et al 2011; Weinberg et al 2013, for reviews). We adopt an empirical method where we sample ICM profiles from high quality X-ray observations of representative galaxy clusters In this way we are able to generate realistic clusters and produce realistic X-ray full sky light-cones of dark matter only N body simulations for eROSITA. This empirical approach is complementary to phenomenological and semi-analytic models, as well as hydrodynamical simulations in that the modeled ICM profiles are non-parametric other than halo mass, redshift, and dynamical state.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
