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Related papers: Measuring Omega_0 using cluster evolution

200 papers

We investigate the redshift evolution of the matter density parameter, $\Omega_m(z)$, using galaxy cluster gas mass fraction measurements combined with cosmic chronometer $H(z)$ data and type Ia supernova luminosity distances. Our approach…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-30 R. F. L. Holanda , J. F. Jesus , Z. C. Santana , R. C. Nunes

The determination of the mean density of the Universe is a long standing problem of modern cosmology. The number density evolution of x-ray clusters at a fixed temperature is a powerful cosmological test, new in nature (Oukbir and…

Astrophysics · Physics 2009-10-30 Alain Blanchard , James G. Bartlett , Rachida Sadat

We examine the likelihoods of different cosmological models and cluster evolutionary histories by comparing semi-analytical predictions of X-ray cluster number counts to observational data from the ROSAT satellite. We model cluster…

Astrophysics · Physics 2009-10-30 B. Mathiesen , A. E. Evrard

We apply a unique gas fraction estimator to published X-ray cluster properties and we compare the derived gas fractions of observed clusters to simulated ones. The observations are consistent with a universal gas fraction of…

Astrophysics · Physics 2007-05-23 Rebecca Danos , Ue-Li Pen

The constraints obtained by several authors (Eke et al. 1998; Henry 2000) on the estimated values of $\Omega_{\rm m}$, $n$ and $\sigma_8$ are revisited in the light of recent theoretical developments: 1) new theoretical mass functions; 2) a…

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

The abundance and mass distribution of galaxy clusters is a sensitive probe of cosmological parameters, through the sensitivity of the high-mass end of the halo mass function to $\Omega_m$ and $\sigma_8$. While galaxy cluster surveys have…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-15 M. Regamey , D. Eckert , R. Seppi , W. Hartley , K. Umetsu , S. Tam , D. Gerolymatou

Measuring the evolution in the clustering of galaxies over a large redshift range is a challenging problem. We have developed a new technique which uses photometric redshifts to measure the angular correlation function in redshift shells.…

Astrophysics · Physics 2007-05-23 Robert J. Brunner , Alex S. Szalay , Andrew J. Connolly

We present precise constraints on the normalization of the power spectrum of mass fluctuations in the nearby universe, sigma_8, as a function of the mean local matter density, Omega_m. Using the observed local X-ray luminosity function of…

Astrophysics · Physics 2008-11-26 S. W. Allen , R. W. Schmidt , A. C. Fabian , H. Ebeling

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

We show that the evolution of the number density of rich clusters of galaxies breaks the degeneracy between Omega (the mass density ratio of the universe) and sigma_{8} (the normalization of the power spectrum), sigma_{8}Omega^{0.5} \simeq…

Astrophysics · Physics 2009-10-30 Neta A. Bahcall , Xiaohui Fan , Renyue Cen

Chandra observations of large samples of galaxy clusters detected in X-rays by ROSAT provide a new, robust determination of the cluster mass functions at low and high redshifts. Statistical and systematic errors are now sufficiently small,…

We forecast the constraints on the values of sigma_8, Omega_m, and cluster scaling relation parameters which we expect to obtain from the XMM Cluster Survey (XCS). We assume a flat Lambda-CDM Universe and perform a Monte Carlo Markov Chain…

The morphology of galaxy clusters reflects the epoch at which they formed and hence depends on the value of the mean cosmological density, Omega. Recent studies have shown that the distribution of dark matter in clusters can be mapped from…

Astrophysics · Physics 2015-06-24 Gillian Wilson , Shaun Cole , Carlos S. Frenk

(abridged) We present a new determination of the local temperature function of X-ray clusters. We use a new sample comprising fifty clusters for which temperature information is now available, making it the largest complete sample of its…

Astrophysics · Physics 2007-05-23 A. Blanchard , R. Sadat , J. G. Bartlett , M. Le Dour

We use current observations on the number statistics of gravitationally lensed optical arcs towards galaxy clusters to derive an upper limit on the cosmological mass density of the Universe. The gravitational lensing statistics due to…

Astrophysics · Physics 2009-10-31 Asantha R. Cooray

We examine the prospects for measuring the dark energy equation of state parameter w within the context of the still uncertain redshift evolution of galaxy cluster structure. We show that for a particular X-ray survey (SZE survey) the…

Astrophysics · Physics 2008-11-26 Subhabrata Majumdar , Joseph J. Mohr

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 time evolution of the number density of galaxy clusters and their mass and temperature functions are used to constrain cosmological parameters in the spatially flat dark matter models containing a fraction of hot particles (massive…

Astrophysics · Physics 2009-11-07 N. A. Arhipova , T. Kahniashvili , V. N. Lukash

The redshift evolution of the galaxy two-point correlation function is a fundamental cosmological statistic. To identify similar galaxy populations at different redshifts, we select a strict volume-limited sample culled from the 6100…

Astrophysics · Physics 2009-10-31 R. G. Carlberg , H. K. C. Yee , S. L. Morris , H. Lin , P. B. Hall , D. Patton , M. Sawicki , C. W. Shepherd

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