相关论文: Baryon Fractions and Cluster Mass Estimates
We investigate if the discrepancy between estimates of the total baryon mass fraction obtained from observations of the cosmic microwave background (CMB) and of galaxy groups/clusters persists when a large sample of groups is considered. To…
Several recent studies used the hot gas fraction of galaxy clusters as a standard ruler to constrain dark energy, which provides competitive results compared to other techniques. This method, however, relies on the assumption that the…
We present a study of the hot gas and stellar content of 5 optically-selected poor galaxy clusters, including a full accounting of the contribution from intracluster light (ICL) and a combined hot gas and hydrostatic X-ray mass analysis…
The baryon fraction of galaxy clusters is a powerful tool to inform on the cosmological parameters while the hot-gas fraction provides indications on the physics of the intracluster plasma and its interplay with the processes driving galaxy…
We study the properties of X-ray galaxy clusters in four cold dark matter models with different baryon fraction $\Omega_{BM}$ ranging from 5 to 20 per cent. By using an original three-dimensional hydrodynamic code based on the piecewise…
We present a statistical analysis of a sample of 20 strong lensing clusters drawn from the Local Cluster Substructure Survey (LoCuSS), based on high resolution Hubble Space Telescope imaging of the cluster cores and follow-up spectroscopic…
I show that three independent methods utilizing clusters of galaxies - cluster dynamics and mass-to-light ratio, baryon fraction in clusters, and cluster evolution - all indicate the same robust result: the mass-density of the universe is…
Groups and clusters of galaxies occupy a special position in the hierarchy of large-scale cosmic structures because they are the largest and the most massive (from ~10^13 Msun to over 10^15 Msun) objects in the universe that have had time…
The different dynamical processes (relaxation, dynamical friction, tides and mergers) operating in groups and clusters are reviewed. The small-scale substructure observed in clusters is argued to be the remnants of the cores of rich…
The luminous material in clusters of galaxies falls primarily into two forms: the visible galaxies and the X-ray emitting intra-cluster medium. The hot intra-cluster gas is the major observed baryonic component of clusters, about six times…
We employ a large sample of 20171 optically-selected groups and clusters at 0.15 < z < 0.4 in the SDSS to investigate how the stacked stellar mass fraction varies across a wide range of total mass, $M_{500}$. Our study improves upon…
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…
The relationships between the X-ray determined bolometric luminosity Lx, the temperature T of the intracluster gas, and the optical measured velocity dispersion sigma of the cluster galaxies are updated for galaxy clusters using the largest…
Results are presented from the analysis of ROSAT HRI and PSPC observations of the CNOC subsample of the EMSS high redshift galaxy clusters. X-ray surface brightness profiles of 14 clusters with $0.17 < z < 0.55$ are constructed and fit to…
We investigate the spatial distribution of the baryonic and non-baryonic mass components in a sample of 66 virialized systems. We have used X-ray measurements to determine the deprojected temperature and density structure of the…
Using a uniform analysis procedure, we measure spatially resolved weak gravitational lensing and hydrostatic X-ray masses for a sample of 18 clusters of galaxies. We find a radial trend in the X-ray to lensing mass ratio: at r2500 we obtain…
The abundance of local clusters is a traditional way to derive the amplitude of matter fluctuations. In the present work, by assuming that the observed baryon content of clusters is representative of the universe, we show that the mass…
Studies of the diffuse X-ray emitting gas in galaxy clusters have provided powerful constraints on cosmological parameters and insights into plasma astrophysics. However, measurements of the faint cluster outskirts have become possible only…
We use cosmological gas dynamic simulations to investigate the accuracy of galaxy cluster mass estimates based on X-ray observations. The experiments follow the formation of clusters in different cosmological models and include the effects…
We present Chandra X-ray measurements of the gas mass fraction out to r500 for a complete sample of the 35 most luminous clusters from the Brightest Cluster Sample and the Extended Brightest Cluster Sample at redshift z=0.15-0.30. The…