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Formation of dark matter halos is sensitive to the expansion rate of the Universe and to the growth of structures under gravitational collapse. Virialization of halos heats the gaseous intra-cluster medium to high temperatures, leading to…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 Nicolas Clerc , Alexis Finoguenov

We show that the hard X-ray (HXR) emission observed from several galaxy clusters is naturally explained by a simple model, in which the nonthermal emission is produced by inverse Compton scattering of cosmic microwave background photons by…

High Energy Astrophysical Phenomena · Physics 2010-02-22 Doron Kushnir , Eli Waxman

Some indications for tension have long been identified between cosmological constraints obtained from galaxy clusters and primary CMB measurements. Typically, assuming the matter density and fluctuations, as parameterized with Omega_m and…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-21 Weiwei Xu , Miriam E. Ramos-Ceja , Florian Pacaud , Thomas H. Reiprich , Thomas Erben

Clusters of galaxies, as the largest virialized systems in the Universe, are ideal laboratories to study the formation and evolution of cosmic structures...(abridged)... Most of the detailed knowledge of galaxy clusters has been obtained in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Luigina Feretti , Gabriele Giovannini , Federica Govoni , Matteo Murgia

Using the simulation of Katz & White we have tested the viability of X-ray analysis for constraining the intrinsic shapes of clusters of galaxies considering the effects of both substructure and steep temperature gradients. We restrict…

Astrophysics · Physics 2009-10-22 D. A. Buote , J. C. Tsai

In this work, the analysis of the stacked projected temperature profile of twelve galaxy clusters of the X-COP sample is performed via the SuperModel, a tool for investigating the intracluster medium thermodynamic properties already tested…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-13 Roberto Fusco-Femiano

We present an extensive study of the double beta model for the X-ray surface brightness profiles of clusters, and derive analytically the gas density and total masses of clusters under the hydrostatic equilibrium hypothesis. It is shown…

Astrophysics · Physics 2009-10-31 Yan-Jie Xue , Xiang-Ping Wu

Large samples of galaxy clusters provide knowledge of both astrophysics in the most massive virialised environments and the properties of the cosmological model that defines our Universe. However, an important issue that affects the…

With the superb angular resolution of the Chandra Observatory, it is now possible to detect X-ray point sources, either embedded in galaxy clusters or along the cluster line of sight, which could not be resolved by previous instruments.…

Astrophysics · Physics 2009-11-11 M. Branchesi , I. M. Gioia , C. Fanti , R. Fanti , N. Cappelluti

In this work, we studied ten nearby ($z$$ \leq$0.038) galaxy clusters to understand possible interactions between hot plasma and member galaxies. A multi-band source detection was applied to detect point-like structures within the…

High Energy Astrophysical Phenomena · Physics 2017-09-04 Turgay Caglar , Murat Hudaverdi

The XMM Cluster Survey (XCS) is a serendipitous search for galaxy clusters using all publicly available data in the XMM-Newton Science Archive. Its main aims are to measure cosmological parameters and trace the evolution of X-ray scaling…

Only a small fraction of galactic nuclei in the nearby universe are luminous; most of them are currently dim. We investigate the feasibility of constraining the X-ray luminosity in the recent past (up to ~10^6 years ago) of the nucleus of a…

Astrophysics · Physics 2009-11-07 S. Sazonov , R. Sunyaev , C. Cramphorn

Based on the two-parameter family nature of X-ray clusters of galaxies obtained in a separate paper, we discuss the formation history of clusters and cosmological parameters of the universe. Utilizing the spherical collapse model of cluster…

Astrophysics · Physics 2009-10-31 Yutaka Fujita , Fumio Takahara

The search for gamma radiation in clusters of galaxies represents a precious tool to investigate the history of these large scale structures. Clusters or sources within them accelerate cosmic rays, as demonstrated by the detection of radio…

Astrophysics · Physics 2007-05-23 Pasquale Blasi

We use a representative sample of 65 galaxy clusters observed with the Einstein IPC to constrain the range of cluster X-ray morphologies. We develop and apply quantitative and reproducible measures to constrain the intrinsic distributions…

Astrophysics · Physics 2016-08-30 J. J. Mohr , A. E. Evrard , D. G. Fabricant , M. J. Geller

We present an analysis of X-ray colour maps of the cores of clusters of galaxies, formed from the ratios of counts in different X-ray bands. Our technique groups pixels lying between contours in an adaptively-smoothed image of a cluster. We…

Astrophysics · Physics 2008-11-26 J. S. Sanders , A. C. Fabian , S. W. Allen

The abundance of galaxy clusters is in principle a powerful tool to constrain cosmological parameters, especially $\Omega_\mathrm{m}$ and $\sigma_8$, due to the exponential dependence in the high-mass regime. While the best observables are…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-23 Christian Angrick , Francesco Pace , Matthias Bartelmann , Mauro Roncarelli

In the currently debated context of using clusters of galaxies as cosmological probes, the need for well-defined cluster samples is critical. The XXL Survey has been specifically designed to provide a well characterised sample of some 500…

Galaxy cluster surveys will be a powerful probe of dark energy. At the same time, cluster abundance is sensitive to any non-Gaussianity of the primordial density field. It is therefore possible that non-Gaussian initial conditions might be…

Astrophysics · Physics 2010-11-05 Emiliano Sefusatti , Chris Vale , Kenji Kadota , Joshua Frieman

Bright clusters of galaxies can be seen out to cosmological distances, and thus they can be used to derive cosmological parameters. Although the continuum X-ray emission from the intra-cluster gas is optically thin, the optical depth of…

Astrophysics · Physics 2009-11-11 S. M. Molnar , M. Birkinshaw , R. F. Mushotzky
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