相关论文: Weak Lensing as a Calibrator of the Cluster Mass-T…
The main uncertainty in current determinations of the power spectrum normalization, sigma_8, from abundances of X-ray luminous galaxy clusters arises from the calibration of the mass-temperature relation. We use our weak lensing mass…
Abundance of rich clusters in local universe is currently believed to provide the most robust normalization of power spectrum at a scale of 10 Mpc. This normalization depends very sensitively on the calibration between virial mass M and…
Scaling relations of observed galaxy cluster properties are useful tools for constraining cosmological parameters as well as cluster formation histories. One of the key cosmological parameters, sigma8, is constrained using observed clusters…
We present weak gravitational lensing analysis of 22 high-redshift (z >~1) clusters based on Hubble Space Telescope images. Most clusters in our sample provide significant lensing signals and are well detected in their reconstructed…
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…
Gravitational lensing can be used to directly constrain the projected density profile of galaxy clusters. We discuss possible future constraints from lensing of the CMB temperature and polarization, and compare to results from galaxy weak…
The scaling between X-ray observables and mass for galaxy clusters and groups is instrumental for cluster based cosmology and an important probe for the thermodynamics of the intracluster gas. We calibrate a scaling relation between the…
We present weak lensing and X-ray analysis of 12 low mass clusters from the CFHTLenS and XMM-CFHTLS surveys. We combine these systems with high-mass systems from CCCP and low-mass systems from COSMOS to obtain a sample of 70 systems,…
Two methods of constraining the properties of dark energy are weak lensing tomography and cluster counting. Uncertainties in mass calibration of clusters can be reduced by using the properties of halo clustering (the clustering of…
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…
A tight mass-temperature relation, M(r)/r ~ T_X, is expected in most cosmological models if clusters of galaxies are homologous and the intracluster gas is in global equilibrium with the dark matter. We here calibrate this relation using 8…
The surface mass density of a cluster of galaxies, and thus its total mass, can be estimated from its lens magnification. The magnification can be determined from the variation in number counts of its background galaxies. In the weak…
In this talk I review some of the key questions that weak lensing observations of clusters can potentially answer, and sketch the progress that has been made to date in extracting quantitative estimates of masses and density profiles. A…
We present the first measurement of the mass function of galaxy clusters based directly on cluster masses derived from observations of weak gravitational lensing. To investigate the degree of sample incompleteness resulting from the X-ray…
The abundance of galaxy clusters is in principle a powerful tool to constrain cosmological parameters, especially $\Omega_\mathrm{m}$ and $\sigma_8$, due to the exponential dependence in the high-mass regime. While the best observables are…
The amplitude of density perturbations, for the currently-favoured LambdaCDM cosmology, is constrained using the observed properties of galaxy clusters. The catalogue used is that of Ikebe et al. (2002). The cluster temperature to mass…
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…
Weak gravitational lensing has been used extensively in the past decade to constrain the masses of galaxy clusters, and is the most promising observational technique for providing the mass calibration necessary for precision cosmology with…
The use of large, X-ray selected galaxy cluster catalogues for cosmological analyses requires a thorough understanding of the X-ray mass estimates. Weak gravitational lensing is an ideal method to shed light on such issues, due to its…
We develop an improved mass tracer for clusters of galaxies from optically observed parameters, and calibrate the mass relation using weak gravitational lensing measurements. We employ a sample of ~ 13,000 optically-selected clusters from…