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Companions to Isolated Elliptical Galaxies: Revisiting the Bothun-Sullivan Sample
We investigate the number of physical companion galaxies for a sample ofrelatively isolated elliptical galaxies. The NASA/IPAC ExtragalacticDatabase (NED) has been used to reinvestigate the incidence of satellitegalaxies for a sample of 34 elliptical galaxies, first investigated byBothun & Sullivan using a visual inspection of Palomar Sky Surveyprints out to a projected search radius of 75 kpc. We have repeatedtheir original investigation using data cataloged in NED. Nine of theseelliptical galaxies appear to be members of galaxy clusters; theremaining sample of 25 galaxies reveals an average of +1.0+/-0.5apparent companions per galaxy within a projected search radius of 75kpc, in excess of two equal-area comparison regions displaced by 150-300kpc. This is significantly larger than the +0.12+/-0.42companions/galaxy found by Bothun & Sullivan for the identicalsample. Making use of published radial velocities, mostly availablesince the completion of the Bothun-Sullivan study, identifies thephysical companions and gives a somewhat lower estimate of +0.4companions per elliptical galaxy. This is still 3 times larger than theoriginal statistical study, but given the incomplete and heterogeneousnature of the survey redshifts in NED, it still yields a firm lowerlimit on the number (and identity) of physical companions. An expansionof the search radius out to 300 kpc, again restricted to sampling onlythose objects with known redshifts in NED, gives another lower limit of4.5 physical companions per galaxy. (Excluding five elliptical galaxiesin the Fornax Cluster, this average drops to 3.5 companions perelliptical.) These physical companions are individually identified andlisted, and the ensemble-averaged radial density distribution of theseassociated galaxies is presented. For the ensemble, the radial densitydistribution is found to have a falloff consistent withρ~R-0.5 out to approximately 150 kpc. For non-FornaxCluster companions the falloff continues out to the 300 kpc limit of thesurvey. The velocity dispersion of these companions is found to reach amaximum of 350 km s-1 at around 120 kpc, after which theyfall at a rate consistent with Keplerian falloff. This falloff may thenindicate the detection of a cut-off in the mass-density distribution inthe elliptical galaxies' dark matter halo at ~100 kpc.
| 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.
| 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.
| 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.
| 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.
| Kinematics of the local universe. VII. New 21-cm line measurements of 2112 galaxies
This paper presents 2112 new 21-cm neutral hydrogen line measurementscarried out with the meridian transit Nan\c cay radiotelescope. Amongthese data we give also 213 new radial velocities which complement thoselisted in three previous papers of this series. These new measurements,together with the HI data collected in LEDA, put to 6 700 the number ofgalaxies with 21-cm line width, radial velocity, and apparent diameterin the so-called KLUN sample. Figure 5 and Appendices A and B forcorresponding comments are available in electronic form at thehttp://www.edpsciences.com
| 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.
| 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
| Optical Rotation Curves and Linewidths for Tully-Fisher Applications
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1997AJ....114.2402C&db_key=AST
| The I band Tully-Fisher relation for cluster galaxies: data presentation.
Observational parameters which can be used for redshift-independentdistance determination using the Tully-Fisher (TF) technique are givenfor \ntot spiral galaxies in the fields of 24 clusters or groups. I bandphotometry for the full sample was either obtained by us or compiledfrom published literature. Rotational velocities are derived either from21 cm spectra or optical emission line long-slit spectra, and convertedto a homogeneous scale. In addition to presenting the data, a discussionof the various sources of error on TF parameters is introduced, and thecriteria for the assignment of membership to each cluster are given.
| Parameters of 2447 Southern Spiral Galaxies for Use in the Tully-Fisher Relation
I-band luminosities, rotational velocities, and redshifts of 1092 spiralgalaxies have been measured by CCD photometry and Hα spectroscopyusing the 1 m and 2.3 m telescopes at Siding Spring Observatory,respectively. The results are tabulated. Luminosity profiles andHα rotation curves are given for the galaxies. When these resultsare combined with similar data for 1355 spiral galaxies publishedpreviously (Mathewson, Ford, & Buchhorn, hereafter Paper I), itprovides a large, uniform, and unique data set with which to measure,via the Tully-Fisher relation, the peculiar velocities of galaxies inthe local universe to a distance of 11,000 km s^-1^ (Mathewson &Ford). Taking advantage of the opportunity for publishing this data inmachine-readable form, in the CD-ROM, we have also included similar datafor the 1355 galaxies in Paper I.
| 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.
| Rotation Curves of 967 Spiral Galaxies
We present the rotation curves of 967 southern spiral galaxies, obtainedby deprojecting and folding the raw Hα data originally publishedby Mathewson, Ford, & Buchhorn (1992). For 900 objects, we alsopresent, in figures and tables, the rotation curves smoothed on scalescorresponding to 5%-20% of the optical size; of these, 80 meet objectiveexcellence criteria and are suitable for individual detailed massmodeling, while 820, individually less compelling mainly because of themoderate statistics and/or limited extension, are suitable forstatistical studies. The remaining 67 curves suffer from severeasymmetries, small statistics, and large internal scatter that maylargely limit their use in galaxy structure studies. The deprojectedfolded curves, the smoothed curves, and various related quantities areavailable via anonymous ftp at galileo.sissa.it in the directory/users/ftp/pub/psrot.
| 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.
| A Preliminary Classification Scheme for the Central Regions of Late-Type Galaxies
The large-scale prints in The Carnegie Atlas of Galaxies have been usedto formulate a classification scheme for the central regions oflate-type galaxies. Systems that exhibit small bright central bulges ordisks (type CB) are found to be of earlier Hubble type and of higherluminosity than galaxies that do not contain nuclei (type NN). Galaxiescontaining nuclear bars, or exhibiting central regions that are resolvedinto individual stars and knots, and galaxies with semistellar nuclei,are seen to have characteristics that are intermediate between those oftypes CB and NN. The presence or absence of a nucleus appears to be auseful criterion for distinguishing between spiral galaxies andmagellanic irregulars.
| The CO and HI emission of spiral and lenticular galaxies in the Fornax cluster.
We present a ^12^CO(1-0) and HI survey of the spirals and lenticulars inthe nearby southern cluster of galaxies Fornax. We have not found anyevidence for a strong HI deficiency in this cluster, which shows weakX-ray emission. However, three lenticular galaxies located near thecluster centre, NGC 1380, NGC 1386 and NGC 1387, present some HIdeficiency with an HI content respectively 50, 25 and 16 times timeslower than expected. On the other hand, the CO emission of Fornaxgalaxies is weak in general and we have clear detections of only 11galaxies out of 21 observed. We have found that on the average, lessthan 10 percent of the gas in these galaxies is in the molecular phase,if the CO to H_2_ conversion factor has the same value as in our galaxy.We have compared these results with those of other extragalactic surveysand found that such low H_2_ contents are characteristic of samples thatare not selected on a far-infrared criterion. In particular the nearbygalaxies surveyed by Sage (1993a, b) also have a low CO emission,although to a lesser level. The low molecular gas content of Fornaxgalaxies is consistent with their low star formation activity suggestedby their low far-infrared and nonthermal radiocontinuum emissions. Wehave made optical spectroscopical observations of the two CO-poorHI-rich spirals NGC 1350 and 1425 and have found that those galaxieshave weak Hα emission. We have also mapped the CO(1-0) and (2-1)emission of the interacting spiral NGC 1532. The CO distribution showstwo maxima at 7kpc radius, compatible with the presence of a molecularring. As most of Fornax spirals NGC 1532 is very poor in molecular gassince it contains about 30 times less H_2_ than HI.
| 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.
| Galaxy properties in different environments. 2: Star formation in bulges of late-type spirals
The star formation history in the nucleus of late spiral galaxies iscompared between a sample in a high galaxy density medium (HDS) and acontrol sample (CS) of isolated galaxies. We have observed 20 HDS and 18CS galaxies from a larger list generated by the application of agroup-finding algorithm to the SSRS survey. Using equivalent widths ofabsorption lines and the continuum distribution, we determined thenuclear stellar population types, from those dominated by old populationto those containing star formation bursts of different ages andintensities. The HDS and CS stellar population type histograms aresimilar, suggesting that environmental influences, at least for thepresent sample, do not affect substantially the nuclear stellarpopulation. However, the nuclear emission lines indicate that, in theBPT diagnostic diagrams, there is an excess of HDS galaxies locatedwithin or close to the active galactic nuclei (AGN) loci. For six HDSand two CS galaxies, it was possible to determine oxygen (O/H) andnitrogen (N/H) abundances. The samples present similar O/H values, butin the CS galaxies the N/O ratio is lower at equal galaxy luminosity.
| Mean morphological types of bright galaxies
The revised Hubble classifications provided in the Third ReferenceCatalogue of Bright Galaxies (RC3) are based on nine lists andcatalogues, both published and unpublished, from five observers. Thispaper describes the procedures that were used to combine theseclassifications into mean classifications including the family, variety,and stage. The best classifications in RC3 are based on large-scalephotographic images taken with 1.5-5 m class reflectors. However, mostof the types in RC3 are based on the small-scale prints, plates, andfilms of the first Palomar Sky Survey and the UK Schmidt IIIa-J SouthernSky Survey. The overlap between the different observers, samples alloweddetermination of the reliability of sky survey types and the effects ofdiameter and inclination on the accuracy of these types. We find thatfor a typical galaxy having isophotal diameter D25approximately = 2 min and inclined by approximately 50 degs, types Tfrom the sky surveys have a mean error (averaged over all of theobservers) of sigma(T) = 0.7 step on the numerical scale of the revisedHubble system. With the new database of classifications, we rederive theclassical relations between Hubble type and integrated colors, surfacebrightnesses, and hydrogen index (hydrogen flux to blue light ratio) fora large sample of galaxies. We also present a table of galaxies which weconsider to be representative examples of each type.
| 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.
| A southern sky survey of the peculiar velocities of 1355 spiral galaxies
The paper presents data from photometric and spectroscopic observationsof 1355 southern spiral galaxies and uses them to determine theirdistances and peculiar velocities via the Tully-Fisher (TF) relation.I-band CCD surface photometry was carried out using the 1-m and 3.9-mtelescopes at Siding Spring Observatory. H-alpha rotation curves for 965galaxies and 551 H I profiles are presented. The physical parameters,photometric and velocity data, distances, and peculiar velocities of thegalaxies are presented in tabular form. The mean distance, systemicvelocity, and average peculiar velocity of 24 clusters in the sample aregiven. TF diagrams are presented for each cluster.
| 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.
| Optical identifications of IRAS point sources - The Fornax, Hydra I and Coma clusters
Optical identifications are presented for 66 IRAS point sources in theregion of the Fornax cluster of galaxies, 106 IRAS point sources in theregion of the Hydra I cluster of galaxies (Abell 1060), and 59 IRASpoint sources in the region of the Coma cluster of galaxies (Abell1656). Eight other sources in Hydra I do not have optical counterpartsand are very probably due to IR cirrus. Twenty-three (35 percent) of theFornax sources are associated with stars and 43 (65 percent) withgalaxies; 48 (42 percent) of the Hydra I sources are associated withstars and 58 (51 percent) with galaxies; 18 (31 percent) of the Comasources are associated with stars and 41 (69 percent) with galaxies. Thestellar and infrared cirrus surface density is consistent with thegalactic latitude of each field.
| 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.
| Automated galaxy surface photometry. IV - Photometric comparisons
Galaxy surface photometry with the Automated Photographic Measuringmachine has been absolutely calibrated by comparison with photoelectricphotometry and CCD images. In the range faintwards of 22.5 bj mag/sqarcsec J-mu, the photometry is consistent between images to 0.05 mag,has sky subtraction errors equal to or less than 0.2 per centcorresponding to 0.05 mag uncertainty at 26 J-mu, and has randomphotometric errors equal to or less than 1 per cent or 0.01 mag.
| 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.
| Revised supernova rates in Shapley-Ames galaxies
Observations of 855 Shapley Ames galaxies made from November 1, 1980 toOctober 31, 1988, together with improved supernova luminosities, havebeen used to derive the frequency of supernovae of different types, andthe results are presented in tables. From a uniform database of 24supernovae discovered, the following SN rates are found, expressed in SNper century per 10 to the 10th L(B)(solar): SN Ia, 0.3; SN Ib, 0.3; andSN II, 1.0. The present data confirm the relatively high frequency of SNII in late-type galaxies that has been found by many previousinvestigators.
| 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.
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