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Redshift-Distance Survey of Early-Type Galaxies: Spectroscopic Data
We present central velocity dispersions and Mg2 line indicesfor an all-sky sample of ~1178 elliptical and S0 galaxies, of which 984had no previous measures. This sample contains the largest set ofhomogeneous spectroscopic data for a uniform sample of ellipticalgalaxies in the nearby universe. These galaxies were observed as part ofthe ENEAR project, designed to study the peculiar motions and internalproperties of the local early-type galaxies. Using 523 repeatedobservations of 317 galaxies obtained during different runs, the dataare brought to a common zero point. These multiple observations, takenduring the many runs and different instrumental setups employed for thisproject, are used to derive statistical corrections to the data and arefound to be relatively small, typically <~5% of the velocitydispersion and 0.01 mag in the Mg2 line strength. Typicalerrors are about 8% in velocity dispersion and 0.01 mag inMg2, in good agreement with values published elsewhere.
| Redshift-Distance Survey of Early-Type Galaxies: Circular-Aperture Photometry
We present R-band CCD photometry for 1332 early-type galaxies, observedas part of the ENEAR survey of peculiar motions using early-typegalaxies in the nearby universe. Circular apertures are used to tracethe surface brightness profiles, which are then fitted by atwo-component bulge-disk model. From the fits, we obtain the structuralparameters required to estimate galaxy distances using theDn-σ and fundamental plane relations. We find thatabout 12% of the galaxies are well represented by a pure r1/4law, while 87% are best fitted by a two-component model. There are 356repeated observations of 257 galaxies obtained during different runsthat are used to derive statistical corrections and bring the data to acommon system. We also use these repeated observations to estimate ourinternal errors. The accuracy of our measurements are tested by thecomparison of 354 galaxies in common with other authors. Typical errorsin our measurements are 0.011 dex for logDn, 0.064 dex forlogre, 0.086 mag arcsec-2 for<μe>, and 0.09 for mRC,comparable to those estimated by other authors. The photometric datareported here represent one of the largest high-quality and uniformall-sky samples currently available for early-type galaxies in thenearby universe, especially suitable for peculiar motion studies.Based on observations at Cerro Tololo Inter-American Observatory (CTIO),National Optical Astronomy Observatory, which is operated by theAssociation of Universities for Research in Astronomy, Inc., undercooperative agreement with the National Science Foundation (NSF);European Southern Observatory (ESO); Fred Lawrence Whipple Observatory(FLWO); and the MDM Observatory on Kitt Peak.
| A catalogue of galaxies behind the southern Milky Way. II. The Crux and Great Attractor regions (l~ 289o to 338o)
In this second paper of the catalogue series of galaxies behind thesouthern Milky Way, we report on the deep optical galaxy search in theCrux region (289o <= l <= 318o and-10o <= b <= 10o) and the Great Attractorregion (316o <= l <= 338o and-10o <= b <= 10o}). The galaxy cataloguesare presented, a brief description of the galaxy search given, as wellas a discussion on the distribution and characteristics of the uncoveredgalaxies. A total of 8182 galaxies with major diameters D >~ 0.2arcmin were identified in this ~ 850 square degree area: 3759 galaxiesin the Crux region and 4423 galaxies in the Great Attractor region. Ofthe 8182 galaxies, 229 (2.8%) were catalogued before in the optical (3in radio) and 251 galaxies have a reliable (159), or likely (92)cross-identification in the IRAS Point Source Catalogue (3.1%). A numberof prominent overdensities and filaments of galaxies are identified.They are not correlated with the Galactic foreground extinction andhence indicative of extragalactic large-scale structures. Redshiftsobtained at the South African Astronomical Observatory (SAAO) for 518 ofthe newly catalogued galaxies in the Crux and Great Attractor regions(Fairall et al. \cite{Fairall98}; Woudt et al. \cite{Woudt99}) confirmdistinct voids and clusters in the area here surveyed. With this opticalgalaxy search, we have reduced the width of the optical ``Zone ofAvoidance'' for galaxies with extinction-corrected diameters larger than1.3 arcmin from extinction levels AB >= 1.0m toAB >= 3.0m: the remaining optical Zone of Avoidance is nowlimited by | b | <~ 3o (see Fig. \ref{cruxf1new}). The twooptical catalogues and their respective listings of IRAScross-identifications are available in electronic format at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/380/441
| Galaxy coordinates. II. Accurate equatorial coordinates for 17298 galaxies
Using 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).
| Extragalactic large-scale structures behind the Southern Milky Way. II. Redshifts obtained at the SAAO in the Crux region
In our systematic optical galaxy search behind the southern Milky Way,3760 (mostly unknown) galaxies with diameters D > 0.2' wereidentified in the Crux region (287° < l < 318°, |b| <10°, cite [Woudt & Kraan-Korteweg 1997]{wo97}). Prior to thisinvestigation, only 65 of these galaxies had known redshifts. In orderto map the galaxy distribution in redshift space we obtained spectra for226 bright (BJ < 18\mag0) objects with the 1.9 m telescopeof the South African Astronomical Observatory (SAAO). Redshifts could bedetermined for 209 objects, of which 173 have good signal-to-noiseratios. Of the 36 tentative redshifts, four are confirmed throughindependent values in the literature. The redshifts of three objectsindicate them to be galactic in origin. One of these confirms asuspected Planetary Nebula. For 17 of the galaxies, no redshift could bedetermined due to poor signal-to-noise ratios. In addition, 26 redshiftshave have been measured in the Hydra-Antlia region investigated earlier(cite [Kraan-Korteweg et al. 1995]{kr95}), of which one is a tentativeestimate. Two main structures crossing the Galactic Plane in the Cruxregion have now become clear. A narrow, nearby filament from (\ell, b) =(340°, -25°) to the Centaurus cluster can be traced. Thisfilament runs almost parallel to the extension of the Hydra-Antliaclusters found earlier and is part of what we have earlier termed the``Centaurus Wall'' extending in redshift-space between 0 <= v <=6000 {km\ s(-1) } (\cite[Fairall & Paverd 1995]{fa95}). The mainoutcome of this survey however, is the recognition of another massiveextended structure between 4000 <= v <= 8000 {{km\ s(-1) }}. Thisbroad structure, dubbed the Norma Supercluster (\cite[Woudt et al.1997]{wou97}), runs nearly parallel to the Galactic Plane from Vela toACO 3627 (its centre) from where it continues to the Pavo cluster. Thismassive structure is believed to be associated with the Great Attractor.The survey has furthermore revealed a set of cellular structures,similar to those seen in redshift space at higher galactic latitudes,but never before seen so clearly behind the Milky Way. All the tablesare only available in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| Redshift Distribution of Galaxies in the Southern Milky Way Region 210 degrees < L < 360 degrees and B < 15 degrees
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996ApJS..107..521V&db_key=AST
| Comparative study of fine structure in samples of isolated and paired early-type galaxies
Fine structure in early-type galaxies is considered to be among the morerobust indicators of a past merging or acquisition event, althoughgrowing evidence from numerical simulations suggests that fine structuremay be also interpreted in a `weak interaction' framework. We present amorphological study of a sample composed of 61 `isolated' early-typegalaxies addressed to the detection of fine structure. This sample hasbeen selected in order to be statistically comparable to a set of 54early-type galaxies, members of pairs analysed by Reduzzi & Rampazzowith a similar technique. The rate of occurrence of fine structuredetected in the `isolated' galaxy sample is significantly higher thanthat found for the pairs. In particular, the fraction of isolatedearly-type galaxies exhibiting shells is 16.4 per cent, a percentagesimilar to that found by Malin & Carter for RC2 isolated objects inthe southern sky, while the fraction of early-type galaxies in pairs is~=4 per cent. We discuss the comparison between the two samples in thecontext of the merger versus the weak interaction origin of finestructures. Concerning the formation of shells, although the mergerorigin cannot be ruled out, the observed difference is more naturallyexplained within the weak interaction framework.
| A search for IRAS galaxies behind the southern Milky Way
We systematically searched for IRAS galaxies with 60 micrometer fluxdensity larger than 0.6 Jy by using the UK Schmidt Infrared and IIIa-JAtlases in the Milky Way region (absolute value of b less than 15 deg)between l = 210 deg and 360 deg. We first selected about 4000 IRAS pointsources by using our far-infrared criteria, which are optimized for thesearch of IRAS galaxies behind the Milky Way region, and then inspectedvisually the optical counterparts of them on the Schmidt Atlas filmcopies. We found 966 IRAS sources associated with galaxy-like objects.The list of the objects is presented here with the IRAS source name,Galactic coordinates, IRAS flux densities, field number and emulsion ofthe Atlas, type and size of galaxy (-like) image, redshift,multiplicity, and cross-identification. Of these, 423 galaxies arealready cataloged in the Catalog of Galaxies and Quasars Observed in theIRAS Survey, and most of the remaining 543 galaxy candidates are newlyidentified in this search. Although the radial velocities are known foronly 387 galaxies, of which 60 were newly measured by us so far, weinferred the contamination by Galactic objects to be small from the goodcorrelation between the sky distributions of the newly identified galaxycandidates and the previously cataloged galaxies. In the regions wherethe Galactic molecular clouds dominate, almost all the sources were notidentified as galaxies. The detected galaxies are clustered in the threeregions around l = 240 deg, 280 deg, and 315 deg, where the projectednumber densities are higher than the whole-sky average of IRAS galaxiesof the same flux limit.
| The supergalactic plane redshift survey
Redshift measurements, about 1000 of which are new, are presented for1314 galaxies in a survey toward the apex of the large-scale streamingflow for ellipticals. The velocity histogram shows that the excess ingalaxy number counts in this area is due to a substantial concentrationof galaxies with discrete peaks at V about 3000 km/s and V about 4500km/s. After correction for the sampling function, the centroid of thedensity distribution is found to be near V about 4500 km/s.Normalization to the more extensive SSRS survey, which was selected bythe same criteria, shows that the region studied contains a considerableoverdensity of galaxies from 2000 to 6000 km/s. This result is in goodagreement with the 'great attractor' model suggested by Lynden-Bell etal. (1988) which attributes the peculiar motions of elliptical galaxiesover a large region of space to an extensive mass overdensity whichincludes the Hydra-Centaurus and Pavo-Indus superclusters. The centroidof the density enhancement is also consistent with new data by Dresslerand Faber (1990) of peculiar motions of elliptical and spiral galaxies,both of which show a zero crossing of the Hubble line at approximately4500-5000 km/s.
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