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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.
| Redshifts for Fainter Galaxies in the First CFA Slice. III. To the Zwicky Catalog Limit
We have measured redshifts for 241 galaxies selected from the Zwickycatalog with magnitudes 15.6 or 15.7 in the region (26.5^deg^ <=32.5^deg^, 8^h^<= α <= 17^h^, 1950). This region is theoriginal CfA "Slice of the Universe," which was complete to 15.5; nownearly all Zwicky-catalog galaxies in the region have measuredredshifts. These somewhat fainter galaxies outline the same structuresas the brighter ones. By examining a sample of 27 galaxies within themost prominent void we find (1) the fraction of absorption-line galaxiesis typical of regions outside the cores of rich clusters; and (2) thelocal morphology- density relation holds within the globally underdensevoid.
| Study of a field in the Coma supercluster. I - Automated galaxies count
A IIIaJ Palomar Schmidt plate of the eastern end of a filament ofgalaxies found by Fontanelli (1984) in the Coma cluster region has beenexamined. The galaxy selection was performed using a classical Bayesianclassification based on the diagram of integrated density versus thearea, allowing all the nonstellar objects to be identified. Coordinates,amplitudes, areas in pixels, and morphological types are given for 7582galaxies. A real-time reduction technique for image segmentation is usedto identify galaxy condensations, and estimations of the parameters,position, axis, and orientation of these condensations are presented.
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