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Companions of Bright Barred Shapley-Ames Galaxies
Companion galaxy environment for a subset of 78 bright and nearby barredgalaxies from the Shapley-Ames Catalog is presented. Among the spiralbarred galaxies, there are Seyfert galaxies, galaxies with circumnuclearstructures, galaxies not associated with any large-scale galaxy cloudstructure, galaxies with peculiar disk morphology (crooked arms), andgalaxies with normal disk morphology; the list includes all Hubbletypes. The companion galaxy list includes the number of companiongalaxies within 20 diameters, their Hubble type, and projectedseparation distance. In addition, the companion environment was searchedfor four known active spiral galaxies, three of them are Seyfertgalaxies, namely, NGC 1068, NGC 1097, and NGC 5548, and one is astarburst galaxy, M82. Among the results obtained, it is noted that theonly spiral barred galaxy classified as Seyfert 1 in our list has nocompanions within a projected distance of 20 diameters; six out of 10Seyfert 2 bar galaxies have no companions within 10 diameters, six outof 10 Seyfert 2 galaxies have one or more companions at projectedseparation distances between 10 and 20 diameters; six out of 12 galaxieswith circumnuclear structures have two or more companions within 20diameters.
| The Frequency of Active and Quiescent Galaxies with Companions: Implications for the Feeding of the Nucleus
We analyze the idea that nuclear activity, either active galactic nuclei(AGNs) or star formation, can be triggered by interactions by studyingthe percentage of active, H II, and quiescent galaxies with companions.Our sample was selected from the Palomar survey and avoids selectionbiases faced by previous studies. This sample was split into fivedifferent groups, Seyfert galaxies, LINERs, transition galaxies, H IIgalaxies, and absorption-line galaxies. The comparison between the localgalaxy density distributions of the different groups showed that in mostcases there is no statistically significant difference among galaxies ofdifferent activity types, with the exception that absorption-linegalaxies are seen in higher density environments, since most of them arein the Virgo Cluster. The comparison of the percentage of galaxies withnearby companions showed that there is a higher percentage of LINERs,transition galaxies, and absorption-line galaxies with companions thanSeyfert and H II galaxies. However, we find that when we consider onlygalaxies of similar morphological types (elliptical or spiral), there isno difference in the percentage of galaxies with companions amongdifferent activity types, indicating that the former result was due tothe morphology-density effect. In addition, only small differences arefound when we consider galaxies with similar Hα luminosities. Thecomparison between H II galaxies of different Hα luminositiesshows that there is a significantly higher percentage of galaxies withcompanions among H II galaxies with L(Hα)>1039 ergss-1 than among those with L(Hα)<=1039ergs s-1, indicating that interactions increase the amount ofcircumnuclear star formation, in agreement with previous results. Thefact that we find that galaxies of different activity types have thesame percentage of companions suggests that interactions betweengalaxies is not a necessary condition to trigger the nuclear activity inAGNs. We compare our results with previous ones and discuss theirimplications.
| Arcsecond Positions of UGC Galaxies
We present accurate B1950 and J2000 positions for all confirmed galaxiesin the Uppsala General Catalog (UGC). The positions were measuredvisually from Digitized Sky Survey images with rms uncertaintiesσ<=[(1.2")2+(θ/100)2]1/2,where θ is the major-axis diameter. We compared each galaxymeasured with the original UGC description to ensure high reliability.The full position list is available in the electronic version only.
| Groups of galaxies. III. Some empirical characteristics.
Not Available
| The Ursa Major Cluster of Galaxies. II. Bimodality of the Distribution of Central Surface Brightnesses
The Ursa Major Cluster appears to be unevolved and made up of H I--richspiral galaxies such as those one finds in the field. B, R, I, K'photometry has been obtained for 79 galaxies, including 62 in a completesample with M^{b,i}B<-16.m5 (with a distance to thecluster of 15.5 Mpc). The K' information is particularly important forthe present discussion because it is not seriously affected byobscuration. There is reasonably convincing evidence that thedistribution of exponential disk central surface brightnesses isbimodal. There is roughly an order of magnitude difference in the meanluminosity densities of high and low surface brightness disks. Disksavoid the domain between the high and low surface brightness zones. Thefew intermediate surface brightness examples in the sample all havesignificant neighbors within a projected distance of 80 kpc. The highsurface brightness galaxies exhibit a range-21^{{m}}
| The Ursa Major Cluster of Galaxies.I.Cluster Definition and Photometric Data
The Ursa Major Cluster has received remarkably little attention,although it is as near as the Virgo Cluster and contains a comparablenumber of H I-rich galaxies. In this paper, criteria for groupmembership are discussed and data are presented for 79 galaxiesidentified with the group. Of these, all 79 have been imaged at B,R,Ibands with CCDs, 70 have been imaged at K' with a HgCdTe array detector,and 70 have been detected in the HI 21 cm line. A complete sample of 62galaxies brighter than M_B_ = - 16.5 is identified. Images and gradientsin surface brightness and color are presented at a common linear scale.As has been seen previously, the galaxies with the reddest global colorsare reddest at the centers and get bluer at large radii. However,curiously, among the galaxies with the bluest global colors there aresystems with very blue cores that get redder at large radii.
| An image database. II. Catalogue between δ=-30deg and δ=70deg.
A preliminary list of 68.040 galaxies was built from extraction of35.841 digitized images of the Palomar Sky Survey (Paper I). For eachgalaxy, the basic parameters are obtained: coordinates, diameter, axisratio, total magnitude, position angle. On this preliminary list, weapply severe selection rules to get a catalog of 28.000 galaxies, wellidentified and well documented. For each parameter, a comparison is madewith standard measurements. The accuracy of the raw photometricparameters is quite good despite of the simplicity of the method.Without any local correction, the standard error on the total magnitudeis about 0.5 magnitude up to a total magnitude of B_T_=17. Significantsecondary effects are detected concerning the magnitudes: distance toplate center effect and air-mass effect.
| A revised catalog of CfA1 galaxy groups in the Virgo/Great Attractor flow field
A new identification of groups and clusters in the CfA1 Catalog ofHuchra et al. is presented, using a percolation algorithm to identifydensity enhancements. It is shown that in the resulting catalog,contamination by interlopers is significantly reduced. The Schechterluminosity function is redetermined, including the Malmquist bias.
| The Infrared Tully-Fisher Relation in the Ursa Major Cluster
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1993ApJ...418..626P&db_key=AST
| 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 list of some corrections to Zwicky's Catalogue of Galaxies and Clusters of Galaxies
Not Available
| Far-infrared luminosity functions of normal galaxies
A volume-limited sample is constructed from the Zwicky catalog and IRASdata base to examine the FIR luminosity functions of normal galaxies,and to investigate possible relationships between FIR emission andgalaxy morphology. Quantitative and unbiased treatment is provided by'survival analysis' statistical methods. It is found that the FIRdistributions of normal galaxies are better fit by lognormal thanSchechter functions. The total FIR emissivity (8 to 115 microns) ofnormal galaxies is approximately equal to half their emission in the Bplus V optical bands. Normal galaxy FIR emission is uncorrelated withthe basic S0-Sm Hubble sequence of spiral galaxy morphology, but appearsto be affected by de Vaucouleurs' (1959) revised morphologicalclassifications based on inner rings and S-shaped arms. Spirals withbars and inner rings are systematically fainter than unbarred spirals.It is suggested that bars and rings reduce the amount or spatiallyconfine the dust in spiral disks, resulting in lower efficiencyconversion of optical and UV photons into the IR.
| Cosmology from a galaxy group catalog. I - Binaries
A new, completely objective group-finding algorithm is described andapplied to the CfA redshift catalog. The binary galaxies are isolatedfor analysis. The assumptions underlying the analysis are (1) that lighttraces mass, (2) that our binary galaxy subsets are representative lighttracers, and (3) that the binary orbits are circular. The primary resultof the work is that the resulting bias-free binary catalogs are afunction of the assumed cosmological model. For virtually any inputvalue of Omega(0) in the range 0.01-5.00, there is a reasonablyconsistent interpretation of the CfA survey such that the specifiedvalue of Omega(0) can be derived from the binary sample obtained underthat interpretation. A secondary result is that the higher the inputvalue of Omega(0), the broader the intrinsic distribution in M/L, andhence the less valid the assumption that light traces mass.
| Supplement to the detailed bibliography on the surface photometry of galaxies
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1985A&AS...60..517P&db_key=AST
| Digital surface photometry of galaxies toward a quantitative classification. III - A mean concentration index as a parameter representing the luminosity distribution
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1984ApJ...280....7O&db_key=AST
| A survey of galaxy redshifts. IV - The data
The complete list of the best available radial velocities for the 2401galaxies in the merged Zwicky-Nilson catalog brighter than 14.5mz and with b (II) above +40 deg or below -30 deg ispresented. Almost 60 percent of the redshifts are from the CfA surveyand are accurate to typically 35 km/s.
| Optical redshifts of 59 galaxies
This paper presents the results of an observing program carried out tomeasure galaxy redshifts with the Cassegrain Digicon Spectrograph systemon the McDonald Observatory 2.1 m Struve telescope. New redshiftdeterminations are presented for 59 galaxies, obtained for emission linespectra by conventional wavelength determination techniques and forabsorption line spectra by Fourier transform filtering and crosscorrelation techniques with respect to velocity standard spectra of NGC3115 and NGC 4736. With respect to published redshifts for 29 galaxies,the new redshifts show a mean residual of -1 km/sec and rms residual of49 km/sec, without apparent systematic trends, from -300 to +13,700km/sec.
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