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Related papers: Using the Evolution of Clusters to Constrain Omega

200 papers

The number of rich galaxy clusters per unit volume is a strong function of Omega, the cosmological density parameter, and sigma_8, the linear extrapolation to z=0 of the density contrast in 8/h Mpc spheres. The CNOC cluster redshift survey…

Astrophysics · Physics 2009-10-28 R. G. Carlberg , S. L. Morris , H. K. C. Yee , E. Ellingson

The evolution of the galaxy cluster abundance depends sensitively on the value of the cosmological density parameter, Omega_0. Recent ASCA data are used to quantify this evolution as measured by the X-ray temperature function. A chi^2…

Astrophysics · Physics 2009-10-30 V. R. Eke , S. Cole , C. S. Frenk , J. P. Henry

Evolution of the cluster population has been recognized as a powerful cosmological tool. While the present--day abundance of X-ray clusters is degenerate in $\sigma_8$, $n$ and $\Omega_0$, Oukbir and Blanchard (1992, 1997) have pointed out…

Astrophysics · Physics 2007-05-23 A. Blanchard , J. G. Bartlett

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

High-resolution N-body simulations of four popular Cold Dark Matter cosmologies (LCDM, OCDM, QCDM, and tilted SCDM), each containing 10^5 clusters of galaxies in a cubic gigaparsec volume, are used to determine the evolution of the cluster…

Astrophysics · Physics 2009-10-31 Paul Bode , Neta A. Bahcall , Eric B. Ford , Jeremiah P. Ostriker

We study the expected redshift evolution of galaxy cluster abundance between 0 < z < 3 in different cosmologies, including the effects of the cosmic equation of state parameter w=p/rho. Using the halo mass function obtained in recent large…

Astrophysics · Physics 2011-05-05 Zoltan Haiman , Joseph J. Mohr , Gilbert P. Holder

We use the observed evolution of the galaxy cluster X-ray integral temperature distribution function between z=0.05 and z=0.32 in an attempt to constrain the value of the density parameter, Omega_0, for both open and spatially-flat…

Astrophysics · Physics 2008-11-26 Pedro T. P. Viana , Andrew R. Liddle

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

The combination of measurements of the local abundance of rich clusters of galaxies and its evolution to higher redshift offers the possibility of a direct measurement of $\Omega_0$ with little contribution from other cosmological…

The geometry of Freedman-Roberston-Walker cosmological models is fixed by the mass density parameter, Omega_M, and the cosmological constant, Omega_Lambda. The classical volume-redshift cosmological relation is a sensitive…

Astrophysics · Physics 2007-05-23 R. G. Carlberg

We present a method for determining the rms mass fluctuations on 8 h^-1 Mpc scale, sigma8. The method utilizes the rate of evolution of the abundance of rich clusters of galaxies. Using the Press-Schechter approximation, we show that the…

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

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

The evolution with redshift of the temperature-luminosity relation of X-ray galaxy clusters is a key ingredient to break degeneracies in the interpretation of X-ray clusters redshift number counts. We therefore take advantage of the recent…

We constrain Omega_m through a maximum likelihood analysis of temperatures and redshifts of the high-redshift clusters from the EMSS. We simultaneously fit the low-redshift Markevitch (1998) sample (an all-sky sample from ROSAT with z=0.04-…

Astrophysics · Physics 2009-10-31 Megan Donahue , G. Mark Voit

From the Press-Schechter mass function and the empirical X-ray cluster luminosity-temperature (L-T) relation, we construct an X-ray cluster luminosity function that can be applied to the growing number of high-redshift, X-ray cluster…

The existence of the three most massive clusters of galaxies observed so far at z>0.5 is used to constrain the mass density parameter of the universe, Omega, and the amplitude of mass fluctuations, sigma_8. We find Omega=0.2 (+0.3,-0.1),…

Astrophysics · Physics 2011-05-05 Neta A. Bahcall , Xiaohui Fan

We have determined the cluster X-ray temperature function from two flux- and redshift-limited samples of clusters. The first sample is comprised of 25 clusters with average redshift 0.05. The local temperature function derived from it…

Astrophysics · Physics 2009-10-31 J. Patrick Henry

X-ray temperature measurements of clusters of galaxies are now reaching to redshifts high enough to constrain Omega_0. A redshift-dependent relation that maps these X-ray temperatures to the virial masses of clusters is an essential…

Astrophysics · Physics 2009-10-30 G. Mark Voit , Megan Donahue

We calculate the all-sky number of galaxy clusters that are expected to be gravitationally lensed by foreground massive clusters. We describe the redshift and number distributions of clusters using a Press-Schechter analysis, and model the…

Astrophysics · Physics 2009-10-30 Asantha R. Cooray , Gilbert P. Holder , Jean M. Quashnock

The CNOC1 cluster survey measures Omega_M via Oort's method, Omega_M= M/L x j/rho_c, where M/L is the field mass-to-light ratio, j is the field luminosity density and rho_c is the closure density. A wide range of potential systematic…

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