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IAUC 8254 available at Central Bureau for Astronomical Telegrams.
| 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.
| The abundance and morphological segregation of dwarf galaxies in the field
Attention has been drawn to the importance of environmental effects,given a strong morphological segregation of the dwarf galaxies. A simplequantitative test for segregation between dwarfs and giants issuggested. The dwarf elliptical (dE) galaxies are considered to beconfined to the clouds and to strongly prefer dense environments on allscales. Their abundance (per giant) is observed to be much lower in thefield than in the clusters and the few dE systems outside of theclusters (i.e., in the clouds) look like companions to the giantgalaxies. Thus, the dwarf galaxies are shown to obey amorphology-density relation in the same way as the giants do, and notonly in the restricted environment of the Virgo cluster.
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