相关论文: Helium abundance in galaxy clusters and Sunyaev-Ze…

In cosmological structure formation models, massive non-linear objects in the process of formation, such as galaxy clusters, are surrounded by large-scale shocks at or around the expected virial radius. Direct observational evidence for…

Studies of cluster X-ray scaling relations have led to suggestions that non-gravitational processes, e.g., radiative cooling and/or "preheating", have significantly modified the entropy of the intracluster medium (ICM). For the first time,…

We examine how the Sunyaev-Zel'dovich (SZ) effect of clusters can probe $\Omega_{o}$. Using self-consistent models of X-ray clusters in the context of hierarchical models of structure formation, we show that both the mean Compton {\it y}…

Scaling relations among galaxy cluster observables, which will become available in large future samples of galaxy clusters, could be used to constrain not only cluster structure, but also cosmology. We study the utility of this approach,…

We compare cluster scaling relations published for three different samples selected via X-ray and Sunyaev-Zel'dovich (SZ) signatures. We find tensions driven mainly by two factors: i) systematic differences in the X-ray cluster observables…

Gas infalling into the gravitational potential wells of massive galaxy clusters is expected to experience one or more shocks on its journey to becoming part of the intracluster medium (ICM). These shocks are important for setting the…

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…

Giant radio haloes in galaxy clusters are the primary evidence for the existence of relativistic particles (cosmic rays) and magnetic fields over Mpc scales. Observational tests for the different theoretical models explaining their powering…

Sensitive surveys of the Cosmic Microwave Background will detect thousands of galaxy clusters via the Sunyaev-Zel'dovich (SZ) effect. Two SZ observables, the central or maximum and integrated Comptonization parameters y_max and Y, relate in…

The relativistic Sunyaev-Zel'dovich (SZ) effect offers a method, independent of X-ray, for measuring the temperature of the intracluster medium (ICM) in the hottest systems. Here, using N-body/hydrodynamic simulations of three galaxy…

We determine the distance to 38 clusters of galaxies in the redshift range 0.14 < z < 0.89 using X-ray data from Chandra and Sunyaev-Zeldovich Effect data from the Owens Valley Radio Observatory and the Berkeley-Illinois-Maryland…

Because of their deep gravitational potential wells, clusters of galaxies retain all the metals produced by the stellar populations of the member galaxies. Most of these metals reside in the hot plasma which dominates the baryon content of…

We have imaged the Sunyaev-Zel'dovich (SZ) effect signals at 140 and 270 GHz towards ten galaxy clusters with Bolocam and AzTEC/ASTE. We also used Planck data to constrain the signal at large angular scales, Herschel-SPIRE images to…

A value of the Hubble constant has been determined from a comparison of the X-ray properties and Sunyaev-Zel'dovich effect of the distant rich cluster of galaxies CL0016+16. The cluster, as imaged by the ROSAT PSPC, is significantly…

Helium abundances and atmospheric parameters have been determined from high resolution spectra for a new sample of 46 bright hot subdwarf B (sdB) stars. The helium abundances have been measured with high accuracy. We confirm the correlation…

This study shows one important effect of preexistent cosmic microwave background temperature fluctuations on the determination of the Hubble constant through Sunyaev-Zel'dovich effect of clusters of galaxies, especially when coupled with…

We investigate the connection between a cluster's structural configuration and observable measures of its gas emission that can be obtained in X-ray and Sunyaev-Zeldovich (SZ) surveys. We present an analytic model for the intracluster gas…

WMAP's detection of the Sunyaev-Zel'dovich effect at a much reduced level among several large samples of rich clusters is interpreted in terms of conventional physics. It has been suggested that the central soft X-ray and EUV excess found…

Cosmological constraints from cluster surveys rely on accurate mass estimates from the mass-observable relations. In order to avoid systematic biases and reduce uncertainties, we study the form and physical origin of the intrinsic scatter…

Over the coming decade, the observational samples available for studies of cluster abundance evolution will increase from tens to hundreds, or possibly to thousands, of clusters. Here we assess the power of future surveys to determine…