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Nearby Optical Galaxies: Selection of the Sample and Identification of Groups
In 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.
| On the morphology of peculiar ring galaxies
It is proposed that peculiar ring galaxies can be divided into fiveprincipal types according to the morphology of the ring and bulge, basedon the visual inspection of 489 selected objects. Those objects havebeen named ``peculiar'' following the ``Catalogue of Southern PeculiarGalaxies and Associations'' by \cite[Arp & Madore (1986]{am6}) Table2 with its notes is only available electronically via anonymous ftp130.79.128.5 or http://cdsweb.u-strasbg.fr.
| The Distribution and Properties of H II Regions in Early-to-Intermediate Hubble Type Ringed Galaxies
This paper presents a study of the H II regions in 32 ringed andpseudo-ringed galaxies having Hubble types in the range S0 + to Sc. Theobjective is to illustrate the distributions of H II regions in classicexamples of ringed galaxies and to relate the observed properties toresonance theory. The sample is selected from the Catalog of SouthernRinged Galaxies and includes examples covering a range of ring andgalaxy morphological properties. We find that the distribution ofHα luminosity around inner rings is sensitive to the intrinsicshape of the rings. Extremely oval inner rings show a greaterconcentration of H II regions near the intrinsic ring major axiscompared to more circular rings. Nuclear rings are present in several ofthe sample galaxies and show a range of morphological properties, from adouble nuclear ring in NGC 1317 to an irregular feature in NGC 1433. Wefind also that in galaxies in which an R_1_ outer ring is prominent inthe continuum image, the H II regions follow an R^'^_2_ morphology. Inseveral cases, the observed distribution of H II regions stronglysupports the idea that the rings are linked to specific orbitalresonances with the bar. H II region luminosity functions have beenderived for all of the sample galaxies. The functions can be representedby power laws whose exponents are very similar to those found fornonringed galaxies. In a few cases, a luminous nuclear ring produces asecondary peak in the luminosity function. One galaxy shows a break inthe luminosity function similar to that observed in other galaxies byKennicutt, Edgar, & Hodge. The most unusual Hα distribution inthe sample was found in the large outer-ringed galaxy NGC 1291. Theprimary bar, lens, and secondary bar regions of this SO/a galaxy arefilled with a wispy pattern of ionized gas filaments very reminiscent ofwhat is seen in the bulge of M31.
| The Catalog of Southern Ringed Galaxies
The Catalog of Southern Ringed Galaxies (CSRG) is a comprehensivecompilation of diameters, axis ratios, relative bar position angles, andmorphologies of inner and outer rings, pseudorings, and lenses in 3692galaxies south of declination -17 deg. The purpose of the catalog is toevaluate the idea that these ring phenomena are related to orbitalresonances with a bar or oval in galaxy potentials. The catalog is basedon visual inspection of most of the 606 fields of the Science ResearchCouncil (SRC) IIIa-J southern sky survey, with the ESO-B, ESO-R, andPalomar Sky surveys used as auxiliaries when needed for overexposed coreregions. The catalog is most complete for SRC fields 1-303 (mostly southof declination -42 deg). In addition to ringed galaxies, a list of 859mostly nonringed galaxies intended for comparison with other catalogs isprovided. Other findings from the CSRG that are not based on statisticsare the identification of intrinsic bar/ring misalignment; bars whichunderfill inner rings; dimpling of R'1pseudorings; pointy, rectangular, or hexagonal inner or outer ringshapes; a peculiar polar-ring-related system; and other extreme examplesof spiral structure and ring morphology.
| The redshift of twelve southern ring galaxies
The redshifts of twelve ring-shaped galaxies from the lists of FM andFaundez-Abans et al. (1992) are evaluated using low-resolutionspectrograms. The spectrographic observations were carried out with the1.6-m telescope at the Laboratorio Nacional de Astrofisica, Brasil. Theclassical distances to the objects are presented.
| Groups of galaxies within 80 Mpc. II - The catalogue of groups and group members
This paper gives a catalog of the groups and associations obtained bymeans of a revised hierarchical algorithm applied to a sample of 4143galaxies with diameters larger than 100 arcsec and redshifts smallerthan 6000 km/s. The 264 groups of galaxies obtained in this way (andwhich contain at least three sample galaxies) are listed, with the looseassociations surrounding them and the individual members of eachaggregate as well; moreover, the location of every entity among 13regions corresponding roughly to superclusters is specified. Finally,1729 galaxies belong to the groups, and 466 to the associations, i.e.,the total fraction of galaxies within the various aggregates amounts to53 percent.
| Southern Sky Redshift Survey - The catalog
The catalog of radial velocities for galaxies which comprise thediameter-limited sample of the Southern Sky Redshift Survey ispresented. It consolidates the data of observations carried out at theLas Campanas Observatory, Observatorio Nacional, and South AfricanAstronomical Observatory. The criteria used for the sample selection aredescribed, as well as the observational procedures and the techniqueutilized to obtain the final radial velocities. The intercomparisonbetween radial velocity measurements from different telescopes indicatesthat the final data base is fairly homogeneous with a typical error ofabout 40 km/s. The sample is at present 90 percent complete, and themissing galaxies are predominantly objects with very low surfacebrightness for which it is very difficult to obtain optical redshifts.
| Weakly barred early-type ringed galaxies. IV - The double-ringed SO(+) galaxy NGC 7702
UBVRI surface photometry of NGC 7702, obtained with a CCD detector onthe 3.9-m Anglo-Australian Telescope and with photographic plates on the4-m telescope at CTIO, is reported. The data are presented in tables,graphs, and contour maps and characterized in detail. NGC 7702 is foundto be a true S0(+) galaxy with a bright high-contrast inner ring and afaint low-contrast outer ring; the inner ring is significantly elongatedrelative to typical SB inner rings and has colors which suggest a burstof star formation less than 2 Gyr ago. A small oval revealed by thebulge isophotes in the inner 4 arcsec radius is attributed to a nuclearbar.
| Southern Galaxy Catalogue.
Not Available
| Redshifts for 228 southern galaxies
In this paper, new redshifts are presented for 228 galaxies locatedsouth of declination -30 deg. The observations were made with aphoton-counting Reticon detector on the Observatorio Nacional (ON)60-in. telescope. The detector is identical to the one used at MountHopkins for the CfA Redshift Survey, and the redshifts were derivedusing the same data-analysis system. A preliminary comparison withpublished 21-cm redshifts indicates that the velocities have azero-point offset of about -4 km/s, with a typical uncertainty of 40km/s. The observations reported here are the initial results of theON-CfA Redshift Survey currently being undertaken in the southernhemisphere.
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