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相关论文: Measuring Cosmological Parameters from the Evoluti…

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(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…

天体物理学 · 物理学 2007-05-23 A. Blanchard , R. Sadat , J. G. Bartlett , M. Le Dour

We use a self-consistent modeling of x-ray cluster properties to constrain cosmological scenarios of structure formation in the case of open cosmological models. We first show that an unbiased open model can reproduce present day…

天体物理学 · 物理学 2019-08-15 J. Oukbir , A. Blanchard

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…

天体物理学 · 物理学 2009-10-30 Alain Blanchard , James G. Bartlett , Rachida Sadat

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…

天体物理学 · 物理学 2008-11-26 Pedro T. P. Viana , Andrew R. Liddle

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…

天体物理学 · 物理学 2008-11-26 S. W. Allen , R. W. Schmidt , A. C. Fabian , H. Ebeling

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…

天体物理学 · 物理学 2009-10-30 V. R. Eke , S. Cole , C. S. Frenk , J. P. Henry

The number density of galaxy clusters provides tight statistical constraints on the matter fluctuation power spectrum normalization, traditionally phrased in terms of sigma_8, the root mean square mass fluctuation in spheres with radius 8…

天体物理学 · 物理学 2011-02-11 J. Patrick Henry , August E. Evrard , Henk Hoekstra , Arif Babul , Andishieh Mahdavi

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…

天体物理学 · 物理学 2009-10-28 R. G. Carlberg , S. L. Morris , H. K. C. Yee , E. Ellingson

Properties of high redshift clusters are a fundamental source of information for cosmology. It has been shown by Oukbir and Blanchard (1997) that the combined knowledge of the redshift distribution of X-ray clusters of galaxies and the…

天体物理学 · 物理学 2011-05-23 R. Sadat , A. Blanchard , J. Oukbir

We present a self-consistent approach to the modeling of X-ray clusters of galaxies in a flat universe. Employing the Press and Schechter (1974) formalism to derive the mass function and relating the observable properties of clusters to…

天体物理学 · 物理学 2016-08-30 J. Oukbir , J. G. Bartlett , A. Blanchard

The population of rich galaxy clusters evolves much more rapidly in a universe with critical density than one with low density, thus offering the possibility of determining the cosmological density parameter, Omega_0. We quantify this…

天体物理学 · 物理学 2015-06-24 Vincent R. Eke , Shaun Cole , Carlos S. Frenk

[Abridged] We use data on massive galaxy clusters ($M_{\rm cluster} > 8 \times 10^{14} h^{-1} M_\odot$ within a comoving radius of $R_{\rm cluster} = 1.5 h^{-1}\Mpc$) in the redshift range $0.05 \lesssim z \lesssim 0.83$ to place…

宇宙学与河外天体物理 · 物理学 2015-05-30 L. Campanelli , G. L. Fogli , T. Kahniashvili , A. Marrone , Bharat Ratra

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…

天体物理学 · 物理学 2007-05-23 A. Blanchard , J. G. Bartlett

We find that the observed log N - log S relation of X-ray clusters can be reproduced remarkably well with a certain range of values for the fluctuation amplitude $\sigma_8$ and the cosmological density parameter $\Omega_0$ in cold dark…

天体物理学 · 物理学 2009-10-30 Tetsu Kitayama , Yasushi Suto

We present precise measurements of the X-ray gas mass fraction for a sample of luminous, relatively relaxed clusters of galaxies observed with the Chandra Observatory, for which independent confirmation of the mass results is available from…

天体物理学 · 物理学 2009-11-07 S. W. Allen , R. W. Schmidt , A. C. Fabian

We derive cosmological constraints using a galaxy cluster sample selected from the 2500~deg$^2$ SPT-SZ survey. The sample spans the redshift range $0.25< z<1.75$ and contains 343 clusters with SZ detection significance $\xi>5$. The sample…

We analyze the ROSAT Deep Cluster Survey (RDCS) to derive cosmological constraints from the evolution of the cluster X-ray luminosity distribution. The sample contains 103 galaxy clusters out to z=0.85 and flux-limit Flim=3 10^{-14} cgs…

Under the assumption that the gas mass fraction of galaxy clusters estimated out to an outer hydrostatic radius is constant, it is possible to constrain the cosmological parameters by using the angular diameter distance relation with…

天体物理学 · 物理学 2011-05-23 Asantha R. Cooray

We present results from a study of the X-ray cluster population that forms within the CLEF cosmological hydrodynamics simulation, a large N-body/SPH simulation of the Lambda CDM cosmology with radiative cooling, star formation and feedback.…

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