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|Dynamics of cD Clusters of Galaxies. III. Redshift Data for 11 Abell Clusters|
We present the final observational data for a spectroscopic study of asample of cD galaxy clusters. The goal of this program has been to studythe dynamics of the clusters, with emphasis on determining the natureand frequency of peculiar-velocity cD galaxies. In this paper we presentredshifts for 762 galaxies in the fields of the rich Abell clustersA779, A1691, A1749, A1767, A1837, A1927, A2067, A2079, A2089, A2199, andA2666. We also present preliminary dynamical properties for theseclusters using our measured redshifts.
|An image database. II. Catalogue between δ=-30deg and δ=70deg.|
A preliminary list of 68.040 galaxies was built from extraction of35.841 digitized images of the Palomar Sky Survey (Paper I). For eachgalaxy, the basic parameters are obtained: coordinates, diameter, axisratio, total magnitude, position angle. On this preliminary list, weapply severe selection rules to get a catalog of 28.000 galaxies, wellidentified and well documented. For each parameter, a comparison is madewith standard measurements. The accuracy of the raw photometricparameters is quite good despite of the simplicity of the method.Without any local correction, the standard error on the total magnitudeis about 0.5 magnitude up to a total magnitude of B_T_=17. Significantsecondary effects are detected concerning the magnitudes: distance toplate center effect and air-mass effect.
|Galaxy structures in the Hercules region|
216 redshifts have been obtained in a region of 981 sq deg south of theHercules supercluster. 172 of these redshifts are of galaxies withmpg less than or equal to 15.1, 110 of which had no previousvelocity measurement. 44 new redshifts are of galaxies fainter thanmpg = 15.1. With these new data we have been able to define asample in a vast region (approximately 1700 sq deg) around Herculeslimited to mpg less than or equal to 15.1 with a velocitycompleteness of 81.5%. 189 galaxies have been morphologically classifiedso that all galaxies in the sample with known velocity now also haveknown morphology. The magnitude limited sample, including 556 galaxies,is then used to identify and describe galaxy structures in the region.We find that the overdense volume is small, that its overall appearanceis that of a coral branch floating in a sea of nothing and that earlyand late type galaxies defined different structures.
|Tests for alignment of galaxy position angles within a sheet of galaxies|
Measured position angles of 149 galaxies that lie in a sheet near thevoid in Corona Borealis are presented. The distribution of positions andposition angles is tested for alignment; none is detected.
|Groups of galaxies in the Center for Astrophysics redshift survey|
By applying the Huchra and Geller (1982) objective group identificationalgorithm to the Center for Astrophysics' redshift survey, a catalog of128 groups with three or more members is extracted, and 92 of these areused as a statistical sample. A comparison of the distribution of groupcenters with the distribution of all galaxies in the survey indicatesqualitatively that groups trace the large-scale structure of the region.The physical properties of groups may be related to the details oflarge-scale structure, and it is concluded that differences among groupcatalogs may be due to the properties of large-scale structures andtheir location relative to the survey limits.
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