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DSS Images Other Images
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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.
| A dynamical analysis of twelve clusters of galaxies
Four-hundred-twenty-eight new redshift measurements for galaxies in thevicinity of 12 Abell clusters are presented. The data are supplementedby previously published data with 3 deg of each cluster center. Thecluster selection, the variety of telescopes and instrumentation used toobtain the galaxy redshifts, and the available X-ray observations arediscussed. Each cluster is exmained in some detail, with the emphasisplaced on the nature of the observed velocity distributions. Robust andresistant estimators of the velocity location and scale are applied inorder to quantify these distributions. The offset in velocity space ofthe dominant galaxy in each cluster or subcluster is considered withrespect to the central location in the velocity space of the cluster asa whole, and the physical implications of significant offsets found inseveral clusters are discussed. Dynamical estimates of the masses ofclusters and/or subclusters are obtained; for clearly bimodal systems,two-body models are employed to specify their likely dynamical state.
| Radio and optical observations of 9 nearby Abell clusters - A262, A347, A569, A576, A779, A1213, A1228, A2162, A2666
A survey is made of 61 Abell clusters included in the HEAO-2 satelliteobserving program at 1.4 GHz. Data are presented on the nine clusters ofdistance class 1 and 2. With a view to establishing galaxy morphologiesand extending the sample of the galaxies with known velocities, platesand spectra are obtained with a 152-cm telescope. The bivariate radioluminosity function of the cluster galaxies is determined for the threemorphological types, E, SO, and S plus Irr, dividing these into threedifferent classes of absolute optical magnitude. The radio luminosityfunctions of E and SO galaxies in present clusters do not differ fromthose of E and SO galaxies in clusters having higher richness. Someevidence exists that spiral galaxies in clusters have a lowerprobability of being radio sources than field ones. Also included is abrief discussion of the sizes of cluster radio sources and thecorrelation between radio emission and the presence of emission linesfrom a galaxy.
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