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 HYPERLEDA. II. The homogenized HI dataAfter a compilation of HI data from 611 references and new observationsmade in Nançay, we produce a catalog of homogenized HI data for16781 galaxies. The homogenization is made using the EPIDEMIC methodfrom which all data are progressively converted into the adoptedstandard. The result is a catalog giving: 1) the logarithm of twice themaximum rotation velocity, log 2V_Msin i, converted to thesystem of Mathewson et al. (\cite{Mathewson1996}). This quantity isgiven without correction for inclination; 2) the HI magnitude,m21, (area of the 21-cm line width expressed in magnitude)converted to the flux system of Theureau et al. (\cite{Theureau1998});3) the HI velocity, V_HI, expressed with the optical definition (i.e.,using wavelengths instead frequencies). The typical uncertainties are:0.04 for log 2V_Msin i, 0.25 mag for m21 and 9 kms-1 for V_HI.Full Tables \ref{epidemicw}, \ref{epidemicw2}, \ref{epidemicf},\ref{epidemicf2} and Fig. \ref{profiles} are available in electronicform at http://www.edpsciences.org. Full Tables \ref{references},\ref{cataf}, \ref{newdata} and \ref{notes} are available in electronicform at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5)or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/412/57 Nearby Optical Galaxies: Selection of the Sample and Identification of GroupsIn this paper we describe the Nearby Optical Galaxy (NOG) sample, whichis a complete, distance-limited (cz<=6000 km s-1) andmagnitude-limited (B<=14) sample of ~7000 optical galaxies. Thesample covers 2/3 (8.27 sr) of the sky (|b|>20deg) andappears to have a good completeness in redshift (97%). We select thesample on the basis of homogenized corrected total blue magnitudes inorder to minimize systematic effects in galaxy sampling. We identify thegroups in this sample by means of both the hierarchical and thepercolation friends-of-friends'' methods. The resulting catalogs ofloose groups appear to be similar and are among the largest catalogs ofgroups currently available. Most of the NOG galaxies (~60%) are found tobe members of galaxy pairs (~580 pairs for a total of ~15% of objects)or groups with at least three members (~500 groups for a total of ~45%of objects). About 40% of galaxies are left ungrouped (field galaxies).We illustrate the main features of the NOG galaxy distribution. Comparedto previous optical and IRAS galaxy samples, the NOG provides a densersampling of the galaxy distribution in the nearby universe. Given itslarge sky coverage, the identification of groups, and its high-densitysampling, the NOG is suited to the analysis of the galaxy density fieldof the nearby universe, especially on small scales. Arcsecond Positions of UGC GalaxiesWe 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. Galaxy coordinates. II. Accurate equatorial coordinates for 17298 galaxiesUsing images of the Digitized Sky Survey we measured coodinates for17298 galaxies having poorly defined coordinates. As a control, wemeasured with the same method 1522 galaxies having accurate coordinates.The comparison with our own measurements shows that the accuracy of themethod is about 6 arcsec on each axis (RA and DEC). Total magnitude, radius, colour indices, colour gradients and photometric type of galaxiesWe present a catalogue of aperture photometry of galaxies, in UBVRI,assembled from three different origins: (i) an update of the catalogueof Buta et al. (1995) (ii) published photometric profiles and (iii)aperture photometry performed on CCD images. We explored different setsof growth curves to fit these data: (i) The Sersic law, (ii) The net ofgrowth curves used for the preparation of the RC3 and (iii) A linearinterpolation between the de Vaucouleurs (r(1/4) ) and exponential laws.Finally we adopted the latter solution. Fitting these growth curves, wederive (1) the total magnitude, (2) the effective radius, (3) the colourindices and (4) gradients and (5) the photometric type of 5169 galaxies.The photometric type is defined to statistically match the revisedmorphologic type and parametrizes the shape of the growth curve. It iscoded from -9, for very concentrated galaxies, to +10, for diffusegalaxies. Based in part on observations collected at the Haute-ProvenceObservatory. Large-Scale Structure at Low Galactic LatitudeWe have extended the CfA Redshift Survey to low galactic latitudes toinvestigate the relation between the Great Wall in the North GalacticCap and the Perseus-Pisces chain in the South Galactic Cap. We presentredshifts for 2020 galaxies in the Catalogue of Galaxies and of Clustersof Galaxies (Zwicky et al. 1961-68, CGCG) in the following regions: 4^h^<= α <= 8^h^, 17^h^ <= α <= 20^h^, 0^deg^ <=δ <= 45^deg^. In these regions, the redshift catalogue includes1664 galaxies with B(0) <= 15.5 (of which 820 are newly measured) andis 97% complete. We also include redshifts for an additional 356galaxies in these regions with B(O) > 15.5; of these, 148 werepreviously unmeasured. The CGCG samples the galaxy distribution down tob_II_ = 10^deg^. In this paper, we discuss the acquisition and reductionof the spectra, and we examine the qualitative features of the redshiftdistribution. The Great Wall and the Perseus-Pisces chain are not simplyconnected across the Zone of Avoidance. These structures, which at firstappear to be coherent on scales of ~100 h^-1^ Mpc or more, actually formthe boundaries of neighboring voids of considerably smaller scale,approximately 50h^-1^ Mpc. The structures delineated by ouroptically-selected sample are qualitatively similar to those detected bythe far-infrared-selected IRAS 1.2 Jansky Survey (Fisher et al. 1995).Although the IRAS survey probes more deeply into the Zone of Avoidance,our optically-selected survey provides better sampling of structures atb_II_ >= 10^deg^. 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. Large-Scale Structures in the Zone of Avoidance: The Galactic Anticenter RegionAbstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995ApJ...449..527L&db_key=AST General study of group membership. II - Determination of nearby groupsWe present a whole sky catalog of nearby groups of galaxies taken fromthe Lyon-Meudon Extragalactic Database. From the 78,000 objects in thedatabase, we extracted a sample of 6392 galaxies, complete up to thelimiting apparent magnitude B0 = 14.0. Moreover, in order to considersolely the galaxies of the local universe, all the selected galaxieshave a known recession velocity smaller than 5500 km/s. Two methods wereused in group construction: a Huchra-Geller (1982) derived percolationmethod and a Tully (1980) derived hierarchical method. Each method gaveus one catalog. These were then compared and synthesized to obtain asingle catalog containing the most reliable groups. There are 485 groupsof a least three members in the final catalog. The kinematics and dynamics of the rich cluster of galaxies Abell 539A sample of 289 redshifts within 10 deg of the center of the clusterA539 have been obtained in order to investigate the cluster kinematicsand dynamics. Within 1 Mpc of the center, the physical parameters ofA539 are found to be typical of those of rich clusters. It is shown thatearly-type galaxies are more concentrated toward the cluster center andthat the velocity distributions of early-type and late-type galaxiesdiffer marginally. U, B, V photometry of nests of interacting galaxiesThe results of three-color photometry of 19 nests of interactinggalaxies are reported. The integrated color indices of nests arecompared with those of normal galaxies in the two-color diagram. Thegreat majority of the objects are found to be blue, some with largeultraviolet excesses. The color indices of the few red nests are typicalof elliptical galaxies, and they evidently consist of E or S0 objects.Some of the low-luminosity blue objects may be irregular or otherindividual galaxies, but the very luminous majority probably consist ofclose groups of coalescent or contiguous galaxies whose emission linesshow the presence of large amounts of gas. Atlas of interacting galaxies, Part. II and the concept of fragmentation of galaxies.Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977A&AS...28....1V&db_key=AST Formation of Satellites by Fragmentation of GalaxiesAbstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974A&A....37..425V&db_key=AST
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