Related papers: The Beta Problem: A Study of Abell 262
The inclination distribution of the Kuiper belt provides unique constraints on its origin and dynamical evolution, motivating vertically resolved observations of extrasolar planetesimal belts. We present ALMA observations of millimeter…
We develop and implement a model to analyze the internal kinematics of galaxy clusters that may contain subpopulations of galaxies that do not independently trace the cluster potential. The model allows for substructures within the cluster…
We study three prominent bi-modal X-ray clusters: A3528, A1750 and A3395. Using observations taken with ROSAT and ASCA, we analyze the temperature and surface brightness distributions. We also analyze the velocity distributions of the three…
We study the temperature structure of the rich cluster of galaxies Abell 1367 using two independent methods of correcting for the ASCA PSF. The results of the two methods are in excellent agreement and give solid evidence of a strong and…
We have analyzed ASCA and ROSAT PSPC spectra and images of the galaxy cluster Abell 2029. The ASCA spectra of the cluster indicate that the gas temperature declines with radius. The PSPC image shows that the cluster is very regular and…
We have performed a uniform analysis of 79 clusters of galaxies with the ROSAT HRI and ASCA to study the X-ray structure and evolution of clusters in the redshift range 0.1 < z < 1. We determined the average X-ray temperatures and the…
The Abell 1689 galaxy cluster has recently become a subject of intensive study. Thanks to its intermediate redshift (z=0.183) its mass distribution can be reconstructed using numerous methods including gravitational lensing, galaxy…
We use ASCA data to obtain two-dimensional maps of the gas temperature in three clusters: A754, A3558 and Triangulum Australis (the maps of A2256, A2319, A2163 and A665, also presented at the conference, have since appeared in [5]). All…
Comparing the observed peculiar velocities of the Local Group and of nearby Abell clusters of galaxies with those predicted using linear perturbation theory and the 3-D reconstruction algorithm of Branchini \& Plionis (1995) the value of…
A total of 663 galaxies with known redshifts in a $6\deg\!\times 6\deg$ field centered on A2634, including 211 new measurements, are used to study the structure of this cluster and its surroundings. Two samples, ---one containing 200…
The relationship between the X-ray determined temperature $T$ of the intracluster gas and the optical measured velocity dispersion $\sigma$ of the cluster galaxies is often believed to be not only a straightforward but also robust test for…
We present new redshift measurements for 55 galaxies in the vicinity of the rich galaxy cluster Abell 665. When combined with results from the literature, we have good velocity measurements for a sample of 77 confirmed cluster members from…
We investigate the possible presence of systematic rotation in the member galaxies of a sample of 17 nearby ($z<0.1$), rich (at least 80 identified members) Abell clusters. We also assess the extent to which low-number statistics may…
The velocity anisotropy profiles, $\beta(r)$, of galaxy clusters are directly related to the shape of the orbits of their member galaxies. Knowledge of $\beta(r)$ is important to understand the assembly process of clusters and the…
We have analyzed spatially resolved spectra of A754 obtained with ASCA. The combination of spectral and imaging capabilities of ASCA has set unprecedented constraints on the hydrodynamical effects of a cluster merger. We find significant…
We present the results of a spectral-imaging analysis of X-ray data obtained with the Position Sensitive Proportional Counter aboard the ROSAT Observatory in a 32 ks pointed observation of Hickson's Compact Group (HCG) #94. Besides HCG94,…
In galaxy cluster collisions, the gas can be separated from dark matter halos. Abell~56 displays signatures of a dissociative bullet-like merger with a possible high inclination angle between the plane of orbit and the sky. Our objective is…
We present direct evidence of a collision of subclusters in the galaxy cluster Abell 754. Our comparison of new optical data and archival ROSAT PSPC X-ray data reveal three collision signatures predicted by n-body/hydrodynamical simulations…
We present results of the X-ray analyses of the nearby cluster of galaxies Abell 2399 ($z=0.058$) using the XMM-Newton and Suzaku satellites. This cluster is classified as a low surface brightness (LSB) cluster. It has a bimodal structure…
We present results from an analysis of a Chandra observation of the cluster of galaxies Abell 3581. We discover the presence of a point-source in the central dominant galaxy which is coincident with the core of the radio source PKS…