Search results for "X-rays: galaxies: clusters"
showing 8 items of 8 documents
Pressure of the hot gas in simulations of galaxy clusters
2016
We analyze the radial pressure profiles, the ICM clumping factor and the Sunyaev-Zel'dovich (SZ) scaling relations of a sample of simulated galaxy clusters and groups identified in a set of hydrodynamical simulations based on an updated version of the TreePM-SPH GADGET-3 code. Three different sets of simulations are performed: the first assumes non-radiative physics, the others include, among other processes, AGN and/or stellar feedback. Our results are analyzed as a function of redshift, ICM physics, cluster mass and cluster cool-coreness or dynamical state. In general, the mean pressure profiles obtained for our sample of groups and clusters show a good agreement with X-ray and SZ observa…
Mass-Metallicity Relation from Cosmological Hydrodynamical Simulations and X-ray Observations of Galaxy Groups and Clusters
2018
Recent X-ray observations of galaxy clusters show that the distribution of intra-cluster medium (ICM) metallicity is remarkably uniform in space and time. In this paper, we analyse a large sample of simulated objects, from poor groups to rich clusters, to study the dependence of the metallicity and related quantities on the mass of the systems. The simulations are performed with an improved version of the Smoothed-Particle-Hydrodynamics \texttt{GADGET-3} code and consider various astrophysical processes including radiative cooling, metal enrichment and feedback from stars and active galactic nuclei (AGN). The scaling between the metallicity and the temperature obtained in the simulations ag…
Shaken Snow Globes: Kinematic Tracers of the Multiphase Condensation Cascade in Massive Galaxies, Groups, and Clusters
2018
We propose a novel method to constrain turbulence and bulk motions in massive galaxies, groups and clusters, exploring both simulations and observations. As emerged in the recent picture of the top-down multiphase condensation, the hot gaseous halos are tightly linked to all other phases in terms of cospatiality and thermodynamics. While hot halos (10^7 K) are perturbed by subsonic turbulence, warm (10^4 K) ionized and neutral filaments condense out of the turbulent eddies. The peaks condense into cold molecular clouds (< 100 K) raining in the core via chaotic cold accretion (CCA). We show all phases are tightly linked via the ensemble (wide-aperture) velocity dispersion along the line o…
Non-thermal pressure support in X-COP galaxy clusters
2018
Galaxy clusters are the endpoints of structure formation and are continuously growing through the merging and accretion of smaller structures. Numerical simulations predict that a fraction of their energy content is not yet thermalized, mainly in the form of kinetic motions (turbulence, bulk motions). Measuring the level of non-thermal pressure support is necessary to understand the processes leading to the virialization of the gas within the potential well of the main halo and to calibrate the biases in hydrostatic mass estimates. We present high-quality measurements of hydrostatic masses and intracluster gas fraction out to the virial radius for a sample of 12 nearby clusters with availab…
Galaxy clusters and groups in the ALHAMBRA survey
2015
Ascaso, Begoña et al.
The XMM Cluster Outskirts Project (X-COP): Thermodynamic properties of the Intracluster Medium out to $R_{200}$ in Abell 2319
2018
We present the joint analysis of the X-ray and SZ signals in A2319, the galaxy cluster with the highest signal-to-noise ratio in Planck maps and that has been surveyed within our XMM Cluster Outskirts Project (X-COP). We recover the thermodynamical profiles by the geometrical deprojection of the X-ray surface brightness, of the SZ comptonization parameter, and an accurate and robust spectroscopic measurements of the temperature. We resolve the clumpiness of the density to be below 20 per cent demonstrating that most of this clumpiness originates from the ongoing merger and can be associated to large-scale inhomogeneities. This analysis is done in azimuthally averaged radial bins and in eigh…
Cosmological hydrodynamical simulations of galaxy clusters: X-ray scaling relations and their evolution
2018
We analyse cosmological hydrodynamical simulations of galaxy clusters to study the X-ray scaling relations between total masses and observable quantities such as X-ray luminosity, gas mass, X-ray temperature, and $Y_{X}$. Three sets of simulations are performed with an improved version of the smoothed particle hydrodynamics GADGET-3 code. These consider the following: non-radiative gas, star formation and stellar feedback, and the addition of feedback by active galactic nuclei (AGN). We select clusters with $M_{500} > 10^{14} M_{\odot} E(z)^{-1}$, mimicking the typical selection of Sunyaev-Zeldovich samples. This permits to have a mass range large enough to enable robust fitting of the r…
Universal thermodynamic properties of the intracluster medium over two decades in radius in the X-COP sample
2018
The hot plasma in galaxy clusters is expected to be heated to high temperatures through shocks and adiabatic compression. The thermodynamical properties of the gas encode information on the processes leading to the thermalization of the gas in the cluster's potential well as well as non-gravitational processes such as gas cooling, AGN feedback and kinetic energy. In this work we present the radial profiles of the thermodynamic properties of the intracluster medium (ICM) out to the virial radius for a sample of 12 galaxy clusters selected from the Planck all-sky survey. We determine the universal profiles of gas density, temperature, pressure, and entropy over more than two decades in radius…