H I content in Coma cluster substructure

Coma Cluster

Completing H I observations of galaxies II . The Coma Supercluster

High sensitivity 21-cm H i line observations, with an rms noise level of ∼ 0.5 mJy, were made of 35 spiral galaxies in the Coma Supercluster, using the refurbished Arecibo telescope, which resulted in the detection of 25 objects. These data, combined with the measurements available from the literature, provide the set of H i data for 94 % of all late-type galaxies in the Coma Supercluster with ...

The Evolution of Cluster Substructure

Using Chandra archival data, we have begun a study to quantify the evolution of cluster morphology with redshift. To quantify cluster morphology, we use the power ratio method developed by Buote and Tsai (1995). Power ratios are constructed from moments of the twodimensional gravitational potential and are, therefore, related to a cluster’s dynamical state. Our sample will include around 50 clu...

ar X iv : a st ro - p h / 01 11 03 8 v 1 2 N ov 2 00 1 Substructure in the Coma Cluster : Giants vs Dwarfs

The processes that form and shape galaxy clusters, such as infall, mergers and dynamical relaxation, tend to generate distinguishable differences between the distributions of a cluster’s giant and dwarf galaxies. Thus the dynamics of dwarf galaxies in a cluster can provide valuable insights into its dynamical history. With this in mind, we look for differences between the spatial and velocity d...

Lithium in the Coma Berenices open cluster

Lithium abundances, radial velocities, and rotational velocities are reported for 20 candidate F, G and K stars of the sparse Coma Berenices open cluster. All the stars are proper-motion selected, and our radial velocities support the membership credentials of at least 12 of the candidates. Combining our data with that in the literature, we have a close-to-complete census of Li abundances for l...