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Related papers: Measuring Omega_m using clusters evolution

200 papers

Context: The evolution of the cluster abundance with redshift is known to be a powerful cosmological constraint when applied to X-ray clusters. Recently, the evolution of the baryon mass function has been proposed as a new variant that is…

Astrophysics · Physics 2009-11-11 S. E. Nuza , A. Blanchard

The observed baryon fraction and velocity--temperature relation in clusters of galaxies are compared with hydrodynamic simulations in two cosmological models : standard (Omega = 1) and a low-density flat (Omega=0.45 and \lambda=0.55) CDM…

Astrophysics · Physics 2009-10-28 Lori M. Lubin , Renyue Cen , Neta A. Bahcall , Jeremiah P. Ostriker

We place constraints on the average density (Omega_m) and clustering amplitude (sigma_8) of matter using a combination of two measurements from the Sloan Digital Sky Survey: the galaxy two-point correlation function, w_p, and the…

We show that the observed mass-to-light ratio of galaxy clusters increases with cluster temperature as expected from cosmological simulations. Contrary to previous observational suggestions, we find a mild but robust increase of M/L from…

Astrophysics · Physics 2009-06-16 Neta A. Bahcall , Julia M. Comerford

We investigate the linear amplitude of mass fluctuations in the universe, $\sigma_8$, and the present mass density parameter of the Universe, $\Omega_\mathrm{m}$, from the statistical strong gravitational lensing. We use the two populations…

Astrophysics · Physics 2014-10-13 Da-Ming Chen

It has become increasingly apparent that traditional hydrodynamical simulations of galaxy clusters are unable to reproduce the observed properties of galaxy clusters, in particular overpredicting the mass corresponding to a given cluster…

Astrophysics · Physics 2009-11-07 Peter A. Thomas , Orrarujee Muanwong , Scott T. Kay , Andrew R. Liddle

We have used recent X-ray and optical data in order to impose some constraints on the cosmology and cluster scaling relations. Generically two kind of hypotheses define our model. First we consider that the cluster population is well…

Astrophysics · Physics 2009-10-31 J. M. Diego , E. Martinez-Gonzalez , J. L. Sanz , L. Cayon , J. Silk

We present a new model for the X-ray properties of the intracluster medium that explicitly includes heating of the gas by the energy released during the evolution of cluster galaxies. We calculate the evolution of clusters by combining the…

Astrophysics · Physics 2009-10-31 R. G. Bower , A. J. Benson , C. G. Lacey , C. M. Baugh , S. Cole , C. S. Frenk

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…

We investigate the gas mass function of clusters of galaxies to measure the density fluctuation spectrum on cluster scales. The baryon abundance confined in rich clusters is computed from the gas mass function and compared with the mean…

Astrophysics · Physics 2009-10-30 Kazuhiro Shimasaku

We use three strong lensing clusters to constrain the cosmological parameters Omega_m and Omega_lambda. Recent HST observations of galaxy clusters reveal a large number of multiple images, which are predicted to be at different redshifts.…

Astrophysics · Physics 2007-05-23 G. Golse , J. -P. Kneib , G. Soucail

We measure the evolution of the velocity dispersion--temperature ($\sigma_{\rm v}$--$T_{\rm X}$) relation up to $z = 1$ using a sample of 38 galaxy clusters drawn from the \textit{XMM} Cluster Survey. This work improves upon previous…

[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…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 L. Campanelli , G. L. Fogli , T. Kahniashvili , A. Marrone , Bharat Ratra

We investigate the luminosity-temperature ($L$-$T$) relation of galaxy clusters as a probe for testing modified gravity (MG) theories, focusing on $f(R)$ gravity and symmetron models. Using an improved semi-analytic framework that…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-31 Antonino Del Popolo , Saeed Fakhry , David F. Mota

We use gravitational lens models and X-ray spectral analysis of ten X-ray luminous galaxy clusters at z~0.2 to study the impact of cluster substructure on attempts to normalize the matter power spectrum. We estimate that unrelaxed clusters…

We present predicted Sunyaev-Zeldovich (SZ) properties of known X-ray clusters of galaxies for which gas temperature measurements are available. The reference sample was compiled from the BAX database for X-ray clusters. The…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Luis Ferramacho , Alain Blanchard

We investigate the potentiality of using strong lensing clusters to constrain the cosmological parameters Omega_m and Omega_lambda. The existence of a multiple image system with known redshift allows, for a given (Omega_m, Omega_lambda)…

Astrophysics · Physics 2009-11-06 G. Golse , J. -P. Kneib , G. Soucail

(Abriged) Assuming that the hydrostatic equilibrium holds between the intracluster medium and the gravitational potential, we constrain the NFW profiles in a sample of 44 X-ray luminous galaxy clusters observed with XMM-Newton in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 S. Ettori , F. Gastaldello , A. Leccardi , S. Molendi , M. Rossetti , D. Buote , M. Meneghetti

We point out a strong time-evolution of the mass-to-light conversion factor \eta commonly used to estimate masses of dense star clusters from observed cluster radii and stellar velocity dispersions. We use a gas-dynamical model coupled with…

Astrophysics · Physics 2009-11-10 C. M. Boily , A. Lacon , S. Deiters , D. C. Heggie

(Abridged) This is the first of a series of papers in which we derive simultaneous constraints on cosmological parameters and X-ray scaling relations using observations of the growth of massive, X-ray flux-selected galaxy clusters. Our data…

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