The Dynamics of the Merging Galaxy Cluster System A2256: Evidence for a New Subcluster

Abstract

We present 236 new radial velocities of galaxies in the cluster A2256 measured with the WIYN Hydra multi-object spectrograph. Combined with the previous work of Fabricant, Kent, and Kurtz (1989), we have velocities for a total of 319 galaxies of which 277 are cluster members. In addition to the new radial velocities, we present a 3x3 image mosaic in the R band of the central 19'x19' region of A2256, from which we obtained photometry for 861 galaxies. These data provide strong evidence for a merger event between two groups. In addition, we present evidence for the presence of a third group, on the outer reaches of the system, that is just now beginning to merge with the system.

submitted to the AJ for publication. (13 figures, 10 tables)

References in corpus (3)

• Chandra observtaion of A2256 - a cluster at the early stage of merging
• RXTE and ASCA Constraints on Non-thermal Emission from the A2256 Galaxy Cluster
• Accelerated Particles from Shocks Formed in Merging Clusters of Galaxies

Cited by in corpus (25)

• The 2MASS Redshift Survey - Description and Data Release
• The Evolution of Substructure in Galaxy, Group and Cluster Haloes I: Basic Dynamics
• Deep 1.4 GHz VLA Observations of the Radio Halo and Relic in Abell 2256
• The duty cycle of radio-mode feedback in complete samples of clusters
• Cool core remnants in galaxy clusters
• Nonthermal Particles and Radiation Produced by Cluster Merger Shocks
• First LOFAR observations at very low frequencies of cluster-scale non-thermal emission: the case of Abell 2256
• Wideband VLA Observations of Abell 2256 I: Continuum, Rotation Measure and Spectral Imaging
• Deep Westerbork observations of Abell 2256 at 350 MHz
• Multiple merging events in Abell 521
• Discovery of Gas Bulk Motion in the Galaxy Cluster Abell 2256 with Suzaku
• Deep low-frequency radio observations of Abell 2256 I: The filamentary radio relic
• Spectral Index Studies of the Diffuse Radio Emission in Abell 2256: Implications to Merger Activity
• A Comprehensive Radio and Optical Study of Abell 2256: Activity from an Infalling Group
• Deep low-frequency radio observations of Abell 2256 II: The ultra-steep spectrum radio halo
• The discovery of diffuse steep spectrum sources in Abell 2256
• JVLA S and X-band Polarimetry of the Merging Cluster Abell 2256
• Supermodel Analysis of Galaxy Clusters
• Chandra and XMM-Newton observations of A2256: cold fronts, merger shocks, and constraint on the IC emission
• Constraining relativistic protons and magnetic fields in galaxy clusters through radio and gamma-ray observations : the case of A2256
• The dynamical state of A548 from XMM-Newton data: X-ray and radio connection
• The Mergers in Abell 2256: Displaced Gas and its Connection to the Radio-emitting Plasma
• Iron abundance distribution in the hot gas of merging galaxy clusters
• Probing particle acceleration in Abell 2256: from to 16 MHz to gamma rays
• Searching in HI for Massive Low Surface Brightness Galaxies: Samples from HyperLeda and the UGC