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S0 galaxies in Fornax: data and kinematics
We have obtained long-slit spectroscopy for a sample of nine S0 galaxiesin the Fornax Cluster using the FORS2 spectrograph at the 8.2-m EuropeanSouthern Observatory (ESO) Very Large Telescope (VLT). From these data,we have extracted the kinematic parameters, comprising the meanvelocity, velocity dispersion and higher moment h3 andh4 coefficients, as a function of position along the majoraxes of these galaxies. Comparison with published kinematics indicatesthat earlier data are often limited by their lower signal-to-noise ratioand relatively poor spectral resolution. The greater depth and higherdispersion of the new data mean that we reach well beyond the bulges ofthese systems, probing their disc kinematics in some detail for thefirst time. Qualitative inspection of the results for individualgalaxies shows that they are not entirely simple systems, perhapsindicating a turbulent past. None the less, we are able to derivereliable circular velocities for most of these systems, which points theway towards a study of their Tully-Fisher relation. This study, alongwith an analysis of the stellar populations of these systems out tolarge galactocentric distances, will form the bases of future papersexploiting these new high-quality data, hopefully shedding new light onthe evolutionary history of these systems.
| The surface brightness and colour-magnitude relations for Fornax cluster galaxies
We present BVI photometry of 190 galaxies in the central 4 ×3deg2 region of the Fornax cluster observed with the MichiganCurtis Schmidt Telescope. Results from the Fornax Cluster SpectroscopicSurvey (FCSS) and the Flair-II Fornax Surveys have been used to confirmthe membership status of galaxies in the Fornax Cluster Catalogue (FCC).In our catalogue of 213 member galaxies, 92 (43 per cent) have confirmedradial velocities.In this paper, we investigate the surface brightness-magnitude relationfor Fornax cluster galaxies. Particular attention is given to the sampleof cluster dwarfs and the newly discovered ultracompact dwarf galaxies(UCDs) from the FCSS. We examine the reliability of the surfacebrightness-magnitude relation as a method for determining clustermembership and find that at surface brightnesses fainter than 22 magarcsec-2, it fails in its ability to distinguish betweencluster members and barely resolved background galaxies. Cluster membersexhibit a strong surface brightness-magnitude relation. Both elliptical(E) galaxies and dwarf elliptical (dE) galaxies increase in surfacebrightness as luminosity decreases. The UCDs lie off the locus of therelation.B-V and V-I colours are determined for a sample of 113 cluster galaxiesand the colour-magnitude relation is explored for each morphologicaltype. The UCDs lie off the locus of the colour-magnitude relation. Theirmean V-I colours (~1.09) are similar to those of globular clustersassociated with NGC 1399. The location of the UCDs on both surfacebrightness and colour-magnitude plots supports the `galaxy threshing'model for infalling nucleated dwarf elliptical (dE, N) galaxies.
| 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 catalog of warps in spiral and lenticular galaxies in the Southern hemisphere
A catalog of optical warps of galaxies is presented. This can beconsidered complementary to that reported by Sánchez-Saavedra etal. (\cite{sanchez-saavedra}), with 42 galaxies in the northernhemisphere, and to that by Reshetnikov & Combes(\cite{reshetnikov99}), with 60 optical warps. The limits of the presentcatalog are: logr 25 > 0.60, B_t< 14.5, delta (2000) <0deg, -2.5 < t < 7. Therefore, lenticular galaxies havealso been considered. This catalog lists 150 warped galaxies out of asample of 276 edge-on galaxies and covers the whole southern hemisphere,except the Avoidance Zone. It is therefore very suitable for statisticalstudies of warps. It also provides a source guide for detailedparticular observations. We confirm the large frequency of warpedspirals: nearly all galaxies are warped. The frequency and warp angle donot present important differences for the different types of spirals.However, no lenticular warped galaxy has been found within the specifiedlimits. This finding constitutes an important restriction fortheoretical models.
| A catalogue and analysis of local galaxy ages and metallicities
We have assembled a catalogue of relative ages, metallicities andabundance ratios for about 150 local galaxies in field, group andcluster environments. The galaxies span morphological types from cD andellipticals, to late-type spirals. Ages and metallicities were estimatedfrom high-quality published spectral line indices using Worthey &Ottaviani (1997) single stellar population evolutionary models. Theidentification of galaxy age as a fourth parameter in the fundamentalplane (Forbes, Ponman & Brown 1998) is confirmed by our largersample of ages. We investigate trends between age and metallicity, andwith other physical parameters of the galaxies, such as ellipticity,luminosity and kinematic anisotropy. We demonstrate the existence of agalaxy age-metallicity relation similar to that seen for local galacticdisc stars, whereby young galaxies have high metallicity, while oldgalaxies span a large range in metallicities. We also investigate theinfluence of environment and morphology on the galaxy age andmetallicity, especially the predictions made by semi-analytichierarchical clustering models (HCM). We confirm that non-clusterellipticals are indeed younger on average than cluster ellipticals aspredicted by the HCM models. However we also find a trend for the moreluminous galaxies to have a higher [Mg/Fe] ratio than the lowerluminosity galaxies, which is opposite to the expectation from HCMmodels.
| Redshift-Distance Survey of Early-Type Galaxies. I. The ENEARc Cluster Sample
This paper presents data on the ENEARc subsample of the larger ENEARsurvey of nearby early-type galaxies. The ENEARc galaxies belong toclusters and were specifically chosen to be used for the construction ofa Dn-σ template. The ENEARc sample includes newmeasurements of spectroscopic and photometric parameters (redshift,velocity dispersion, line index Mg2, and the angular diameterdn), as well as data from the literature. New spectroscopicdata are given for 229 cluster early-type galaxies, and new photometryis presented for 348 objects. Repeat and overlap observations withexternal data sets are used to construct a final merged catalogconsisting of 640 early-type galaxies in 28 clusters. Objectivecriteria, based on catalogs of groups of galaxies derived from completeredshift surveys of the nearby universe, are used to assign galaxies toclusters. In a companion paper, these data are used to construct thetemplate Dn-σ distance relation for early-typegalaxies, which has been used to estimate galaxy distances and derivepeculiar velocities for the ENEAR all-sky sample. Based on observationsat Complejo Astronomico El Leoncito, operated under agreement betweenthe Consejo Nacional de Investigaciones Científicas de laRepública Argentina and the National Universities of La Plata,Córdoba, and San Juan; Cerro Tololo Inter-American Observatory,National Optical Astronomical Observatory, which is operated by theAssociation of Universities for Research in Astronomy, Inc., undercooperative agreement with the National Science Foundation; the EuropeanSouthern Observatory (ESO), partially under the ESO-ON agreement; theFred Lawrence Whipple Observatory; the Observatório do Pico dosDias, operated by the Laboratório Nacional de Astrofísicaand the MDM Observatory at Kitt Peak.
| The neutral hydrogen content of Fornax cluster galaxies
We present a new set of deep H I observations of member galaxies of theFornax cluster. We detected 35 cluster galaxies in HI. The resulting sample, the most comprehensive to date, is used toinvestigate the distribution of neutral hydrogen in the clustergalaxies. We compare the H I content of the detected cluster galaxieswith that of field galaxies by measuring H I mass-to-light ratios andthe H I deficiency parameter of Solanes et al. (\cite{Sol96}). The meanH I mass-to-light ratio of the cluster galaxies is 0.68+/- 0.15,significantly lower than for a sample of H I-selected field galaxies(1.15+/- 0.10), although not as low as in the Virgocluster (0.45+/- 0.03). In addition, the H I content of twocluster galaxies (NGC 1316C and NGC1326B) appears to have been affected by interactions. The meanH I deficiency for the cluster is 0.38+/-0.09 (for galaxy types T=1-6),significantly greater than for the field sample (0.05+/-0.03). Boththese tests show that Fornax cluster galaxies are HI-deficient compared to field galaxies. The kinematics of the clustergalaxies suggests that the H I deficiency may be caused by ram-pressurestripping of galaxies on orbits that pass close to the cluster core. Wealso derive the most complete B-band Tully - Fisher relation of inclinedspiral galaxies in Fornax. A subcluster in theSouth-West of the main cluster contributes considerably to the scatter.The scatter for galaxies in the main cluster alone is 0.50 mag, which isslightly larger than the intrinsic scatter of 0.4 mag. We use the Tully- Fisher relation to derive a distance modulus ofFornax relative to the Virgocluster of -0.38+/- 0.14 mag. The galaxies in the subclusterare (1.0+/-0.5) mag brighter than the galaxies of the main cluster,indicating that they are situated in the foreground. With their meanvelocity 95 km s-1 higher than that of the main cluster weconclude that the subcluster is falling into the main Fornaxcluster.
| The stellar populations of early-type galaxies in the Fornax cluster
We have measured central line strengths for a magnitude-limited sampleof early-type galaxies in the Fornax cluster, comprising 11 elliptical(E) and 11 lenticular (S0) galaxies, more luminous thanMB=-17. When compared with single-burst stellar populationmodels we find that the centres of Fornax ellipticals follow a locus offixed age and have metallicities varying roughly from half solar totwice solar. The centres of (lower luminosity) lenticular galaxies,however, exhibit a substantial spread to younger luminosity-weightedages, indicating a more extended star formation history. Galaxies withold stellar populations show tight scaling relations between metal-lineindices and the central velocity dispersion. Remarkably also, the Felines are well correlated with σ0. Our detailedanalysis of the stellar populations suggests that these scalingrelations are driven mostly by metallicity. Galaxies with a youngstellar component do generally deviate from the main relation. Inparticular, the lower luminosity S0s show a large spread. Ourconclusions are based on several age/metallicity diagnostic diagrams inthe Lick/IDS system comprising established indices such asMg2 and Hβ as well as new and more sensitive indicessuch as HγA and Fe3, a combination of three prominentFe lines. The inferred difference in the age distribution betweenlenticular and elliptical galaxies is a robust conclusion, as the modelsgenerate consistent relative ages using different age and metallicityindicators, even though the absolute ages remain uncertain. The absoluteage uncertainty is mainly caused by the effects of non-solar abundanceratios which are not yet accounted for by the stellar population models.Furthermore, we find that elliptical galaxies and the bulge of onebright S0 are overabundant in magnesium, where the most luminousgalaxies show the strongest overabundances. The stellar populations ofyoung and faint S0s are consistent with solar abundance ratios or a weakMg underabundance. Two of the faintest lenticular galaxies in our samplehave blue continua and extremely strong Balmer-line absorption,suggesting star formation <2Gyr ago.
| Tracing the vertical composition of disc galaxies through colour gradients
Optical observations of a statistically complete sample of edge-ondisc-dominated galaxies are used to study the intrinsic vertical colourgradients in the galactic discs, in order to constrain the effects ofpopulation gradients, residual dust extinction and gradients in themetal abundance of the galaxies. For the majority of our samplegalaxies, the colours and colour gradients in the range1.0hz<=|z|<=3.0hz most likely reflect theintrinsic galactic properties (where hz is the verticalscaleheight). It appears that the intrinsic vertical colour gradientsare either non-existent, or small and relatively constant as a functionof position along the major axes of the galaxies. On average, theearlier-type galaxies exhibit smaller vertical (B-I) gradients than thelater types; our results are consistent with the absence of any verticalcolour gradient in the discs of the early-type sample galaxies. In mostgalaxies small-scale variations in the magnitude and even the directionof the vertical gradient are observed: at larger galactocentricdistances they generally display redder colours with increasing zheight, whereas the opposite is often observed in and near the galacticcentres. For a significant fraction of our sample galaxies anothermechanism in addition to the effects of stellar population gradients isrequired to explain the magnitude of the observed gradients. Thenon-zero colour gradients in a significant fraction of our samplegalaxies are likely to be (at least) partially due to residual dustextinction at these z heights, as is also evidenced from the sometimessignificant differences between the vertical colour gradients measuredon either side of the galactic planes. We suggest that initial verticalmetallicity gradients, if any, have probably not been accentuated byaccretion or merging events over the lifetimes of our sample galaxies.On the other hand, they may have weakened any existing verticalmetallicity gradients, although they also may have left the existingcorrelations unchanged.
| 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.
| Box- and peanut-shaped bulges. I. Statistics
We present a classification for bulges of a complete sample of ~ 1350edge-on disk galaxies derived from the RC3 (Third Reference Catalogue ofBright Galaxies, de Vaucouleurs et al. \cite{rc3}). A visualclassification of the bulges using the Digitized Sky Survey (DSS) inthree types of b/p bulges or as an elliptical type is presented andsupported by CCD images. NIR observations reveal that dust extinctiondoes almost not influence the shape of bulges. There is no substantialdifference between the shape of bulges in the optical and in the NIR.Our analysis reveals that 45% of all bulges are box- and peanut-shaped(b/p). The frequency of b/p bulges for all morphological types from S0to Sd is > 40%. In particular, this is for the first time that such alarge frequency of b/p bulges is reported for galaxies as late as Sd.The fraction of the observed b/p bulges is large enough to explain theb/p bulges by bars. Partly based on observations collected at ESO/LaSilla (Chile), DSAZ/Calar Alto (Spain), and Lowell Observatory/Flagstaff(AZ/U.S.A.). Tables 6 and 7 are only available in electronic form at CDSvia anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| 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).
| The global structure of galactic discs
A statistical study of global galaxy parameters can help to improve ourunderstanding of galaxy formation processes. In this paper we presentthe analysis of global galaxy parameters based on optical andnear-infrared observations of a large sample of edge-on disc galaxies.We found a correlation between the ratio of the radial to vertical scaleparameter and galaxy type: galaxies become systematically thinner whengoing from type S0 to type Sc, whereas the distribution seems to leveloff for later types. The observed scalelength ratios (and thus theradial colour gradients) largely represent the dust content of thegalaxies. On average, the colour gradients indicated by the scalelengthratios increase from type Sa to at least type Sc. For galaxy types laterthan Sc, the average colour gradient seems to decrease again. Thedistribution of K-band (edge-on) disc central surface brightnesses israther flat, although with a large scatter. However, the latest-typesample galaxies (T>6) show an indication that their average disccentral surface brightnesses may be fainter than those of the earliertypes. This effect is probably not the result of dust extinction.
| The Southern Sky Redshift Survey
We report redshifts, magnitudes, and morphological classifications for5369 galaxies with m_B <= 15.5 and for 57 galaxies fainter than thislimit, in two regions covering a total of 1.70 sr in the southerncelestial hemisphere. The galaxy catalog is drawn primarily from thelist of nonstellar objects identified in the Hubble Space TelescopeGuide Star Catalog (GSC). The galaxies have positions accurate to ~1"and magnitudes with an rms scatter of ~0.3 mag. We compute magnitudes(m_SSRS2) from the relation between instrumental GSC magnitudes and thephotometry by Lauberts & Valentijn. From a comparison with CCDphotometry, we find that our system is homogeneous across the sky andcorresponds to magnitudes measured at the isophotal level ~26 magarcsec^-2. The precision of the radial velocities is ~40 km s^-1, andthe redshift survey is more than 99% complete to the m_SSRS2 = 15.5 maglimit. This sample is in the direction opposite that of the CfA2; incombination the two surveys provide an important database for studies ofthe properties of galaxies and their large-scale distribution in thenearby universe. Based on observations obtained at Cerro TololoInter-American Observatory, National Optical Astronomy Observatories,operated by the Association of Universities for Research in Astronomy,Inc., under cooperative agreement with the National Science Foundation;Complejo Astronomico El Leoncito, operated under agreement between theConsejo Nacional de Investigaciones Científicas de laRepública Argentina and the National Universities of La Plata,Córdoba, and San Juan; the European Southern Observatory, LaSilla, Chile, partially under the bilateral ESO-ObservatórioNacional agreement; Fred Lawrence Whipple Observatory;Laboratório Nacional de Astrofísica, Brazil; and the SouthAfrican Astronomical Observatory.
| Total magnitude, radius, colour indices, colour gradients and photometric type of galaxies
We 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.
| A catalogue of spatially resolved kinematics of galaxies: Bibliography
We present a catalogue of galaxies for which spatially resolved data ontheir internal kinematics have been published; there is no a priorirestriction regarding their morphological type. The catalogue lists thereferences to the articles where the data are published, as well as acoded description of these data: observed emission or absorption lines,velocity or velocity dispersion, radial profile or 2D field, positionangle. Tables 1, 2, and 3 are proposed in electronic form only, and areavailable from the CDS, via anonymous ftp to cdsarc.u-strasbg.fr (to130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html
| The z-structure of disk galaxies towards the galaxy planes
We present a detailed study of a statistically complete sample of highlyinclined disk galaxies in the near-infrared K' band. Since the K'-bandlight is relatively insensitive to contamination by galactic dust, wehave been able to follow the vertical light distributions all the waydown to the galaxy planes. The mean levels for the sharpness of theK'-band luminosity peaks indicate that the vertical luminositydistributions are more peaked than expected for the intermediate sech(z)distribution, but rounder than exponential. After fitting a generalizedfamily of fitting functions characterised by an exponent 2/n (n = inftyfor exponential, n = 2 for sech and n = 1 for sech(2) ; van der Kruit1988) we find that the mean value for 2/n in the K' band equals<2/n>_{K'} = 0.538, sigma_ {K'} = 0.198. Since projection of notcompletely edge-on galaxies onto the plane of the sky causes verticalluminosity profiles to become rounder, we have performed simulationsthat show that it is possible that all our galaxies can haveintrinsically exponential vertical surface brightness distributions. Wefind that the profile shape is independent of galaxy type, and varieslittle with position along the major axis. The fact that we observe thisin all our sample galaxies indicates that the formation process of thegalaxy disks perpendicular to the galaxy planes is a process intrinsicto the disks themselves. Based on observations obtained at the EuropeanSouthern Observatory, La Silla, Chile
| A New I-Band Tully-Fisher Relation for the Fornax Cluster: Implication for the Fornax Distance and Local Supercluster Velocity Field
The Fornax Cluster represents an important step in the extragalacticdistance scale. Here we present a new I-band luminosity-H I velocitywidth (I-band Tully-Fisher) study of the cluster using an enlargedsampled of spiral galaxies in Fornax. I-band CCD photometry and 21 cmparameters are measured for 23 members of Fornax and compared with datafor the Virgo Cluster. We obtain an accurate distance modulus of Fornaxrelative to Virgo of -0.06 +/- 0.15 mag. The low scatter of Fornaxgalaxies around the Tully-Fisher relation will make the cluster an idealcalibrator once a direct measurement of its distance is obtained.Furthermore, the H I content of the galaxies does not seem affected bythe cluster environment. Here we use two different absolute calibrationmethods which yield an absolute distance to Fornax of 15.4 +/- 2.3 Mpc(absolute distance modulus of 30.94 +/- 0.33 mag). A simple model yieldsa Local Group Virgocentric flow velocity of 224 +/- 90 km s^-1^ whichcorresponds to a Hubble constant of H_0_ = 74 +/- 11 km s^-1^ Mpc^-1^from the Fornax data.
| New aperture photometry for 217 galaxies in the Virgo and Fornax clusters.
We present photo electric multi-aperture photometry in UBVRI of 171 and46 galaxies in the Virgo and Fornax clusters, respectively. Many of thegalaxies have not been observed in at least one of these passbandsbefore. We discuss the reduction and transformation into the Cousinsphotometric system as well as the extinction coefficients obtainedbetween 1990 and 1993.
| The fundamental plane of early-type galaxies: stellar populations and mass-to-light ratio.
We analyse the residuals to the fundamental plane (FP) of ellipticalgalaxies as a function of stellar-population indicators; these are basedon the line-strength parameter Mg_2_ and on UBVRI broad-band colors, andare partly derived from new observations. The effect of the stellarpopulations accounts for approximately half the observed variation ofthe mass-to-light ratio responsible for the FP tilt. The residual tiltcan be explained by the contribution of two additional effects: thedependence of the rotational support, and possibly that of the spatialstructure, on the luminosity. We conclude to a constancy of thedynamical-to-stellar mass ratio. This probably extends to globularclusters as well, but the dominant factor would be here the luminositydependence of the structure rather than that of the stellar population.This result also implies a constancy of the fraction of dark matter overall the scalelength covered by stellar systems. Our compilation ofinternal stellar kinematics of galaxies is appended.
| A Catalog of Stellar Velocity Dispersions. II. 1994 Update
A catalog of central velocity dispersion measurements is presented,current through 1993 September. The catalog includes 2474 measurementsof 1563 galaxies. A standard set of 86 galaxies is defined, consistingof galaxies with at least three reliable, concordant measurements. It issuggested that future studies observe some of these standard galaxies sothat different studies can be normalized to a consistent system. Allmeasurements are reduced to a normalized system using these standards.
| Major axis kinematics of 15 early-type galaxies in the Fornax cluster.
Major axis rotation curves and velocity dispersions profiles, extendingout to about one effective radius, are presented for 15 ellipticals andS0's out of the photometric sample of Fornax cluster galaxies studied byCaon et al. (1994). A brief description of the spectroscopic andphotometric characteristics of each galaxy is provided, together with acomparison with previous studies. Six of the nine E's are possiblymisclassified S0's or ellipticals harboring a disk-like component. Twogalaxies (NGC 1399 and 1404) show a hint of counter-rotation. Evidenceis given that the bright and the ordinary families of early-typegalaxies, first introduced by Capaccioli et al. (1992), look distinctalso in term of the anisotropy parameter (V_m_/σ)*.
| Galaxy properties in different environments. 1: The sample
This paper presents two galaxy samples, respectively in a high and in alow local density environments, that were generated from the SouthernSky Redshift Survey (SSRS) catalog using objective criteria. Apreliminary comparison of physical properties in these two samplesreveals that galaxies in high-density environments tend to be under ahigher starbursting activity, have a deficiency of the neutral hydrogencontent, present a higher fractional Seyfert population and a higherfraction of barred spirals as well. The present samples are intended tobe used in future spectroscopic observations for more detailedinvestigation.
| 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.
| 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.
| A catalog of southern groups of galaxies
A catalog of groups of galaxies identified in the southern Galactic capis presented. This catalog was constructed utilizing the group-findingalgorithm developed by Huchra and Geller (1982) to analyze galaxysamples with well-defined selection criteria and complete velocityinformation.
| Population studies in groups and clusters of galaxies. II - A catalog of galaxies in the central 3.5 deg of the Fornax Cluster
A catalog of 2678 galaxies within an area of about 40 sq deg centered onthe Fornax Cluster has been compiled based on 26 deep large-scale platesobtained with the 2.5-m Las Campanas Observatory reflector. The catalogincludes 340 likely cluster members and 2338 likely background galaxies.Radial velocities are given for 89 of the galaxies. The spatialdistributions of various types of galaxies have been modeled as the sumof a King (1962) model cluster component superimposed on a uniformbackground. Using maximum-likelihood fits to these distributions, a coreradius of 0.7 deg is found for a King model fit to the cluster,suggesting that there are few cluster members contained in the sample ofbackground galaxies.
| A southern redshift survey. I - Accurate redshifts for 500 galaxies observed at SAAO
Radial velocities are presented for about 500 galaxies observed with anintensified Reticon photon-counting detector attached to the 1.9 mtelescope at the Sutherland field station of SAAO. The velocities weredetermined by cross correlation with standard velocity templates, fromthe measured wavelengths of emission lines, or from both techniques,with spectra covering the wavelength range from 3700 to 5400 A. Thefinal velocities appear to have the same zero point as H I radiovelocities, and have standard deviations of the order of 35 km/s, thoughcross-correlation velocities on their own may have significantly largererrors.
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