We present the first results of an optical follow-up of X-ray bright clusters of galaxies located between 0.15<=z<=0.31: B and R photometry as well as medium resolution spectroscopy of the galaxies. The cluster studied here - A1300 - is found to have a redshift of 0.3072 and a velocity dispersion of 1210km/s, based on 52 cluster members. Structures are observed in the galaxy number counts but the velocity histogram shows no significant departure from a Gaussian distribution.
We present the results of a study on galaxy interactions, tides, and other processes that produce luminous fine-scale substructures in the galaxy clusters: Coma, Perseus, Abell 2199, AWM 3, and AWM 5. All unusual structures in these clusters can be categorized into seven morphologies: interacting galaxies, multiple galaxies (noninteracting), distorted galaxies, tailed galaxies, line galaxies, dwarf galaxy groups, and galaxy aggregates. The various morphologies are described, and a catalog is presented, of 248 objects in these five clusters along with color, and positional information obtained from CCD images taken with the WIYN 3.5 m telescope in broadband B and R filters.
The cluster Abell 2104 is one of the lowest redshift clusters (z=0.153) known to have a gravitational lensing arc. We present detailed analysis of the cluster properties such as the gravitational potential using the X-ray data from ROSAT (HRI) and ASCA, as well as optical imaging and spectroscopic data from the CFHT.
We present the results of a photometric and spectroscopic study of seven members of the NGC 5328 group of galaxies, a chain of galaxies spanning over 200kpc (H0=70km/s/Mpc). We analyse the galaxy structure and study the emission-line properties of the group members looking for signatures of star formation and active galactic nucleus activity. We finally attempt to infer, from the modelling of line-strength indices, the stellar population ages of the early-type members.
A catalogue of 1192 galaxies in the central regions (30' x 30') of 11 clusters in the Ursa Major supercluster is presented. For each galaxy equatorial and relative coordinates and total B and R_c_ magnitudes and B-R_c_ colour are given. Plates taken with the 2-m Tautenburg Observatory telescope and CCD images obtained with the 6-m and 1-m SAO telescopes are used.
We present the optical spectroscopy for the Blind Ultra Deep HI Environmental Survey (BUDHIES). With the Westerbork Synthesis Radio Telescope, BUDHIES has detected HI in over 150 galaxies in and around two Abell clusters at z=~0.2. With the aim of characterizing the environments of the Hi-detected galaxies, we obtained multifibre spectroscopy with the William Herschel Telescope. In this paper, we describe the spectroscopic observations, report redshifts and EW[OII] measurements for ~600 galaxies, and perform an environmental analysis. In particular, we present cluster velocity dispersion measurements for five clusters and groups in the BUDHIES volume, as well as a detailed substructure analysis.
We explore the internal structure of red-sequence galaxies in the Coma cluster across a wide range of luminosities (-17>M_g_>-22) and cluster-centric radii (0<r_cluster_<1.3r_200_). We present the 2D bulge-disc decomposition of galaxies in deep Canada-France-Hawaii Telescope u, g, i imaging using GALFIT. Rigorous filtering is applied to identify an analysis sample of 200 galaxies which are well described by an 'archetypal' S0 structure (central bulge + outer disc).
We present BVI photometry of 190 galaxies in the central 4x3deg^2^ region of the Fornax cluster observed with the Michigan Curtis Schmidt Telescope. Results from the Fornax Cluster Spectroscopic Survey (FCSS) and the Flair-II Fornax Surveys have been used to confirm the membership status of galaxies in the Fornax Cluster Catalogue (FCC, Cat. <VII/180>). In our catalogue of 213 member galaxies, 92 (43 per cent) have confirmed radial velocities.
We have used the 2.3-meter Vainu Bappu Telescope to perform CCD imaging of X-ray-selected poor clusters of galaxies. Our sample consists of four X-ray luminous clusters in the Einstein Observatory Extended Medium Sensitivity Survey (EMSS) and noted by Gioia & Luppino (1994ApJS...94..583G) to be optically less rich than Abell clusters. The sample spans a redshift range of 0.08<=z<=0.22. We have assembled catalogs of galaxies detected in the cluster fields to a magnitude limit m_V_~22. This paper describes the data reduction performed on the CCD images, the methods used to construct the extended object catalogs, the photometric calibrations, and some understanding of their completeness and contamination.
We have obtained deep and wide field imaging of the Coma cluster of galaxies with the CFH12K camera at CFHT in the B, V, R and I filters. In this paper, we present the observations, data reduction, catalogs and first scientific results. We investigated the quality of our data by internal and external literature comparisons. We also checked the realisation of the observational requirements we set. Images are available at http://cencosw.oamp.fr
