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The ESO nearby Abell cluster survey. VIII. Morphological and spectral classification of galaxies
We determine the morphological types of 2295 galaxies from the ESONearby Abell Cluster Survey (ENACS) from CCD images obtained with theDutch telescope on La Silla. A comparison with morphological types fromthe literature for 450 of our galaxies shows that the reliability of ourclassification is quite comparable to that of other classifiers. Werecalibrate the ENACS spectral classification with the new morphologicaltypes, and find that early- and late-type galaxies can be distinguishedfrom their spectra with 83% reliability. Ellipticals and S0 galaxies canhardly be distinguished on the basis of their spectra, but late spiralscan be classified from the spectrum alone with more than 70%reliability. We derive pseudo-colors and linestrengths from the ENACSspectra for the galaxies of different morphological types. We considerthe bright (MR ≤ -20) and faint (MR > -20)subsets of the galaxies without emission lines (non-ELG) separately. Wefind a strong and significant correlation between the average color andthe average strength of the metal absorption lines. The averagemetallicity decreases and the average color gets bluer towards laterHubble type. Also, the faint galaxies in each morphological class arebluer and less metal-rich than their brighter counterparts, whichextends the well-established color-magnitude relation of early-typegalaxies to (late) spirals. In view of these very strong global trends,the colors and metallicities of faint S0 galaxies and bright earlyspirals are remarkably similar. The bright early spirals may, onaverage, have somewhat stronger Hδ absorption than the othergalaxies, which could be due to recent starformation. The galaxies withemission lines (ELG) have a bluer spectral continuum than the non-ELG,and the amount of blueing hardly depends on morphological type. Thefraction of ELG depends strongly on morphological type (varying from4±1% for ellipticals to 59±4% for late spirals), but foreach of the morphological types it varies very little with projecteddistance from the cluster center.
| FLASH redshift survey - I. Observations and catalogue
The FLAIR Shapley-Hydra (FLASH) redshift survey catalogue consists of4613 galaxies brighter than bJ= 16.7 (corrected for Galacticextinction) over a 700-deg2 region of sky in the generaldirection of the Local Group motion. The survey region is a70°× 10° strip spanning the sky from the ShapleySupercluster to the Hydra cluster, and contains 3141 galaxies withmeasured redshifts. Designed to explore the effect of the galaxyconcentrations in this direction (in particular the Supergalactic planeand the Shapley Supercluster) upon the Local Group motion, the 68 percent completeness allows us to sample the large-scale structure betterthan similar sparsely-sampled surveys. The survey region does notoverlap with the areas covered by ongoing wide-angle (Sloan or 2dF)complete redshift surveys. In this paper, the first in a series, wedescribe the observation and data reduction procedures, the analysis forthe redshift errors and survey completeness, and present the surveydata.
| The ESO Nearby Abell Cluster Survey. V. The catalogue: Contents and instructions for use
We present the catalogue resulting from the ESO Nearby Abell ClusterSurvey (the ENACS), which contains redshifts and magnitudes for 5634galaxies in the directions of 107 rich, nearby southern Abell clustercandidates. We describe the contents of the catalogue and discuss theresults of a comparison between the ENACS catalogue and the COSMOSGalaxy Catalogue. When cross-correlating the two catalogues we findthat, at least in the areas of the ENACS clusters, the completeness ofthe COSMOS catalogue is somewhat lower than was estimated previously forthe carefully analyzed and well-calibrated part of the COSMOS catalogueknown as the Edinburgh-Durham Southern Galaxy Survey (EDSGC). The galaxypositions in the COSMOS and ENACS catalogues are found to be on the samesystem to within about one arcsecond. For the clusters for which thephotometry in the ENACS and COSMOS catalogues is based on the samesurvey plates, the two magnitude scales agree very well. We confirm thatthe photometric calibration in the EDSGC subset of the COSMOS catalogueis of higher quality than in the EDSGC complement. The ENACS galaxysamples are unbiased subsets of the COSMOS catalogue as far as theprojected galaxy distribution is concerned, except in only a few cases.We summarize how the ENACS galaxy samples are subsets of the COSMOScatalogues in the ENACS apertures, with respect to magnitude. For theENACS catalogue as a whole, we describe the apparent incompleteness atfaint magnitudes and towards higher redshifts. Finally, we provide somedetailed information about the ENACS catalogue that is essential for itsproper statistical use and we summarize some facts that must beremembered when selecting subsets of galaxies from it. Based onobservations collected at the European Southern Observatory (La Silla,Chile).
| 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.
| General study of group membership. II - Determination of nearby groups
We 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.
| Redshift observations in the Centaurus-Hydra supercluster region. I
The paper presents 111 new redshifts in the region of theCentaurus-Hydra supercluster. Also presented is the growth of theHydra-Centaurus structures as a function of the percolation vector, thesurface distribution of galaxies in this region, and the distribution inredshift of the observed galaxies.
| A comparison of distance scales for early-type galaxies
The distance scales of elliptical and lenticular galaxies areintercompared, based on the velocity dispersion indicator derived from arevised Faber-Jackson relation. The scales are found to be in nearperfect agreement with scales derived from the luminosity index and fromthe 21 cm line width indicator. The scales are also in excellentagreement with the distance scale derived by Michard (1979). Additionsare offered for the general catalog of 424 early-type galaxies, and aseries of reduction equations is presented which reduces the externalerrors in the distance moduli.
| Redshifts in Klemola 27
Observational data for galaxies in the galaxy cluster Klemola 27gathered over the last few years are presented. These are mostly newredshifts and further, accurate coordinates and morphological types fora large number of 'prominent' galaxies in the ESO/SRC-Survey fields 444and 445. A few preliminary H I radial velocities are also reported. Thedata available for this cluster are briefly discussed.
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