We perform a joint analysis of the counts of redMaPPer clusters selected from the Dark Energy Survey (DES) year 1 data and multiwavelength follow-up data collected within the 2500 deg 2 South Pole Telescope (SPT) Sunyaev-Zel'dovich (SZ) survey. The SPT follow-up data, calibrating the richness-mass relation of the optically selected redMaPPer catalog, enable the cosmological exploitation of the DES cluster abundance data. To explore possible systematics related to the modeling of projection effects, we consider two calibrations of the observational scatter on richness estimates: a simple Gaussian model which account only for the background contamination (BKG), and a model which further includes contamination and incompleteness due to projection effects (PRJ). Assuming either a ΛCDM þ P m ν or wCDM þ P m ν
We use observations of stacked X-ray luminosity and Sunyaev-Zel'dovich (SZ) signal from a cosmological sample of ∼ 80, 000 and 104, 000 massive galaxies, respectively, with 10 12.6 M 500 10 13 M ⊙ and mean redshift,z ∼ 0.1 -0.14 to constrain the hot Circumgalactic Medium (CGM) density and temperature. The X-ray luminosities constrain the density and hot CGM mass, while the SZ signal helps in breaking the density-temperature degeneracy. We consider a simple power-law density distribution (n e ∝ r −3β ) as well as a hydrostatic hot halo model, with the gas assumed to be isothermal in both cases. The datasets are best described by the mean hot CGM profile ∝ r −1.2 , which is shallower than an NFW profile. For halo virial mass ∼ 10 12 -10 13 M ⊙ , the hot CGM contains ∼ 20 -30% of galactic baryonic mass for the powerlaw model and 4 -11% for the hydrostatic halo model, within the virial radii. For the power-law model, the hot CGM profile broadly agrees with observations of the Milky Way. The mean hot CGM mass is comparable to or larger than the mass contained in other phases of the CGM for L * galaxies.
The abundance of galaxy clusters as a function of mass and redshift is a well known powerful cosmological probe, which relies on underlying modelling assumptions on the mass-observable relations (MOR). MOR parameters have to be simultaneously fit together with the parameters describing the cosmological model. Some of the MOR parameters can be constrained directly from multi-wavelength observations, as the normalization at some reference cosmology, the mass-slope, the redshift evolution and the intrinsic scatter. However, the cosmology dependence of MORs cannot be tested with multi-wavelength observations alone. We use Magneticum simulations to explore the cosmology dependence of galaxy cluster scaling relations. We run fifteen different hydro-dynamical cosmological simulations varying Ω m , Ω b , h 0 and σ 8 (around a reference cosmological model). The MORs considered in this work are gas mass, gas temperature, Y and velocity dispersion as a function of the spherical overdensity virial mass. We verify that the mass and redshift slopes and the intrinsic scatter of the MORs are nearly independent of cosmology with variations significantly smaller than current observational uncertainties. We show that the gas mass sensitively depends only on the baryon fraction, velocity dispersion and gas temperature sensitively depend on the hubble constant, and Y depends on both baryon fraction and the hubble constant. We investigate the cosmological implications of our MOR parameterization on a mock catalog created for an idealized eROSITA-like experiment. We show that our parametrization introduces a strong degeneracy between the cosmological parameters and the normalization of the MOR, degeneracy that can be broken by combining multiple observables and hence improve the cosmological parameter constraints. Finally, the parameter constraints derived at different overdensity (∆ 500c ), for X-ray bolometric gas luminosity and stellar mass, and for different subgrid physics prescriptions are shown in the appendix.
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