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Arcsecond Positions of UGC Galaxies
We present accurate B1950 and J2000 positions for all confirmed galaxiesin the Uppsala General Catalog (UGC). The positions were measuredvisually from Digitized Sky Survey images with rms uncertaintiesσ<=[(1.2")2+(θ/100)2]1/2,where θ is the major-axis diameter. We compared each galaxymeasured with the original UGC description to ensure high reliability.The full position list is available in the electronic version only.
| The Ursa Major Cluster of Galaxies.I.Cluster Definition and Photometric Data
The Ursa Major Cluster has received remarkably little attention,although it is as near as the Virgo Cluster and contains a comparablenumber of H I-rich galaxies. In this paper, criteria for groupmembership are discussed and data are presented for 79 galaxiesidentified with the group. Of these, all 79 have been imaged at B,R,Ibands with CCDs, 70 have been imaged at K' with a HgCdTe array detector,and 70 have been detected in the HI 21 cm line. A complete sample of 62galaxies brighter than M_B_ = - 16.5 is identified. Images and gradientsin surface brightness and color are presented at a common linear scale.As has been seen previously, the galaxies with the reddest global colorsare reddest at the centers and get bluer at large radii. However,curiously, among the galaxies with the bluest global colors there aresystems with very blue cores that get redder at large radii.
| 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.
| Northern dwarf and low surface brightness galaxies. II - The Green Bank neutral hydrogen survey
The paper reports neutral hydrogen observations of a large sample ofdwarf and other low surface brightness galaxies. A detailed discussionand error analysis of the observations are presented, and spectra aredisplayed for 329 galaxies detected for the first time, or detected withsubstantially better signal-to-noise ratios than achieved previously.The positions on the sky of 667 galaxies meeting the present selectioncriteria north of delta = 38 deg are shown. The distribution of theredshifts of galaxies detected at Green Bank is illustrated. The GreenBank detections tapered off strongly below the median H I flux of 3.7 Jykm/s detected at Arecibo: only 12 percent of the Green Bank sample wasdetected with smaller fluxes.
| 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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