English
Related papers

Related papers: Constraints on $\Omega_\mathrm{m}$ and $\sigma_8$ …

200 papers

We present constraints on the mean matter density, Omega_m, the normalization of the density fluctuation power spectrum, sigma_8, and the dark-energy equation-of-state parameter, w, obtained from measurements of the X-ray luminosity…

Astrophysics · Physics 2010-02-03 A. Mantz , S. W. Allen , H. Ebeling , D. Rapetti

We take advantage of the biggest cosmological simulation to date for a critical CDM universe in order to test robustness of the cluster mass function on a range of masses much wider than tested before. On the high mass end our results show…

Astrophysics · Physics 2007-05-23 P. Tozzi , F. Governato

Cosmological constraints from clusters rely on accurate gravitational mass estimates, which strongly depend on cluster gas temperature measurements. Therefore, systematic calibration differences may result in biased, instrument-dependent…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-18 G. Schellenberger , T. H. Reiprich , L. Lovisari , J. Nevalainen , L. David

Combining conservation of energy throughout nearly-spherical collapse of galaxy clusters with the virial theorem, we derive the mass-temperature relation for X-ray clusters of galaxies $T=CM^{2/3}$. The normalization factor $C$ and the…

Astrophysics · Physics 2009-08-29 Niayesh Afshordi , Renyue Cen

Many approaches to obtaining cosmological constraints rely on the connection between galaxies and dark matter. However, the distribution of galaxies is dependent on their formation and evolution as well as the cosmological model, and galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 Rachel Reddick , Jeremy Tinker , Risa Wechsler , Yu Lu

We show how to improve constraints on \Omega_m, \sigma_8, and the dark-energy equation-of-state parameter, w, obtained by Mantz et al. (2008) from measurements of the X-ray luminosity function of galaxy clusters, namely MACS, the local BCS…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-04 A. Del Popolo , V. Costa , G. Lanzafame

Evolution of the cluster temperature function is extremely sensitive to the mean matter density of the universe. Current measurements based on cluster temperature surveys indicate that Omega_M ~ 0.3 with a 1-sigma statistical error ~0.1,…

Astrophysics · Physics 2009-10-31 G. M. Voit

(Abridged) This is the second in a series of papers in which we derive simultaneous constraints on cosmology and X-ray scaling relations using observations of massive, X-ray flux-selected galaxy clusters. The data set consists of 238…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Adam Mantz , Steven W. Allen , Harald Ebeling , David Rapetti , Alex Drlica-Wagner

Observations and numerical simulations have shown that the relation between the mass scaled with the critical density of the universe and the X-ray temperature of galaxy clusters is approximately represented by $M_\Delta \propto T_X^{3/2}$…

Astrophysics of Galaxies · Physics 2018-08-15 Yutaka Fujita , Keiichi Umetsu , Stefano Ettori , Elena Rasia , Nobuhiro Okabe , Massimo Meneghetti

The recent tension in the value of the cosmological parameter $S_8 \equiv \sigma_8(\Omega_M/0.3)^{1/2}$, which represents the amplitude of the matter density fluctuations of the universe, has not been resolved. In this work, we present…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-02 Erwin T. Lau , Ákos Bogdán , Daisuke Nagai , Nico Cappelluti , Masato Shirasaki

Context. We present an estimation of cosmological parameters with clusters of galaxies. Aims. We constrain the $\Omega_m$, $\sigma_8$, and $w$ parameters from a stand-alone sample of X-ray clusters detected in the 50 deg$^2$ XMM-XXL survey…

In this paper, I revisit the constraints obtained by several authors (Reichart et al. 1999; Eke et al. 1998; Henry 2000) on the estimated values of Omega_m, n and sigma_8 in the light of recent theoretical developments: 1) new theoretical…

Astrophysics · Physics 2009-11-10 A. Del Popolo

The growth of structure in the Universe is tightly correlated with the cosmological parameters. Galaxy clusters as tracers of the large scale structure are the ideal objects to witness this evolution. The X-ray bright, hot gas in the…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-09 G. Schellenberger , T. H. Reiprich

The mass of galaxy clusters can be inferred from the temperature of their X-ray emitting gas, $T_{\mathrm{X}}$. Their masses may be underestimated if it is assumed that the gas is in hydrostatic equilibrium, by an amount…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Holger Israel , Gerrit Schellenberger , Jukka Nevalainen , Richard Massey , Thomas Reiprich

Cosmological parameters such as $\Omega_{\rm{M}}$ and $\sigma_{8}$ can be measured indirectly using various methods, including galaxy cluster abundance and cosmic shear. These measurements constrain the composite parameter $S_{8}$, leading…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-27 Roan Haggar , Yuba Amoura , Charlie T. Mpetha , James E. Taylor , Kris Walker , Chris Power

We analyse parallel N-body simulations of three Cold Dark Matter (CDM) universes to study the abundance and clustering of galaxy clusters. The simulations cover a volume comparable to the forthcoming SDSS. We are able to make robust…

Astrophysics · Physics 2008-11-26 F. Governato , A. Babul , T. Quinn , P. Tozzi , C. M. Baugh , N. Katz , G. Lake

Galaxy clusters can be used as powerful cosmological probes, provided one can obtain accurate mass estimates, which requires a precise knowledge of the underlying astrophysics of galaxy clusters. For these purposes, spatially resolved…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-12 R. Wicker , M. De Petris , A. Ferragamo , I. Bartalucci , G. Yepes , E. Rasia , R. Adam , W. Cui , F. Mayet , L. Perotto , M. Muñoz-Echeverría

Forthcoming large galaxy cluster surveys will yield tight constraints on cosmological models. It has been shown that in an idealized survey, containing > 10,000 clusters, statistical errors on dark energy and other cosmological parameters…

Astrophysics · Physics 2008-11-26 Joshua D. Younger , Zoltan Haiman , Greg L. Bryan , Sheng Wang

Results from a large sample of hydrodynamical/N-body simulations of galaxy clusters in a LCDM cosmology are used to simulate cluster X-ray observations as expected from Chandra observations. The physical modeling of the gas includes…

Astrophysics · Physics 2009-11-11 R. Valdarnini

A new X-ray selected and X-ray flux-limited galaxy cluster sample is presented. Based on the ROSAT All-Sky Survey the 63 brightest clusters with galactic latitude |bII| >= 20 deg and flux fx(0.1-2.4 keV) >= 2 * 10^{-11} ergs/s/cm^2 have…

Astrophysics · Physics 2011-02-11 Thomas H. Reiprich , Hans Boehringer