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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 UZC-SSRS2 Group Catalog|
We apply a friends-of-friends algorithm to the combined Updated ZwickyCatalog and Southern Sky Redshift Survey to construct a catalog of 1168groups of galaxies; 411 of these groups have five or more members withinthe redshift survey. The group catalog covers 4.69 sr, and all groupsexceed the number density contrast threshold, δρ/ρ=80. Wedemonstrate that the groups catalog is homogeneous across the twounderlying redshift surveys; the catalog of groups and their membersthus provides a basis for other statistical studies of the large-scaledistribution of groups and their physical properties. The medianphysical properties of the groups are similar to those for groupsderived from independent surveys, including the ESO Key Programme andthe Las Campanas Redshift Survey. We include tables of groups and theirmembers.
|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.
|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.|
|Catalogue of HI maps of galaxies. I.|
A catalogue is presented of galaxies having large-scale observations inthe HI line. This catalogue collects from the literature the informationthat characterizes the observations in the 21-cm line and the way thatthese data were presented by means of maps, graphics and tables, forshowing the distribution and kinematics of the gas. It containsfurthermore a measure of the HI extension that is detected at the levelof the maximum sensitivity reached in the observations. This catalogueis intended as a guide for references on the HI maps published in theliterature from 1953 to 1995 and is the basis for the analysis of thedata presented in Paper II. The catalogue is only available inelectronic form at the CDS via anonymous ftp 184.108.40.206 orhttp://cdsweb.u-strasbg.fr/Abstract.html
|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.
|Measuring the Hubble constant and our Virgo-infall velocity independently|
A sample of spiral galaxies with BT less than 14.5 located intwo local volumes, one in the direction of, but behind, the VirgoCluster (behind-Virgo volume (BV)) and the other in the oppositedirection (anti-Virgo volume (AV)), were used via a Tully-Fisher (TF)relation to derive the following two parameters: HAB, themean Hubble ratio between AV and BV, and delta vparallel, thepeculiar velocity of the Local Group in the direction of the VirgoCluster (VC) with respect to a uniformly expanding reference systemdefined by our AV and BV sub-samples. The two sampled volumes, separatedby a velocity interval of 5600 km/s, form an antipodal pair. Thisparticular geometry not only allows us to derive the two parametersindependently but also reduces the dynamical effect of the LocalSupercluster on HAB without increasing the Malmquist bias. Bylimiting our sample to spiral galaxies having large velocity widthsWR, we effectively reduce the TF scatter and Malmquist biasin our sample. The TF zero point and dispersion were then determined byfurther correcting for the small residual Malmquist bias. An additionalsample of fainter galaxies was used to test for a non-Gaussian tail tothe TF disperison. We found no evidence for such a tail and formallygive an upper limit of about 18% for the fractional contribution of anunseen tail. The average intrinsic TF dispersion for the dominantGaussian component is sigmaTF0 approximately 0.33mag for WR approximately equal to or greater than 180 km/s.Our numerical results are delta vparallel approximatelyequals 414 +/- 82 km/s and HAB approximately equals (84.0 +/-2.4)(1 + epsilon) km/s Mpc, where (1 + epsilon) accounts for anysystematic error between the calibrators and the sample galaxies.Various dynamical models were tested to explore the effect onHAB of the uncertainties in the local velocity field.Constrained by our observed delta vparallel as well as otherobservational quantities, we found that the rms deviation from unity ofHAB/H0 (where H0 is the Hubble constantfor each model) is 5%, making HAB a good indicator forH0. Taking this variation as an additional error, our formalestimate for the Hubble constant is H0 approximately equals(84 +/- 5)(1 + epsilon) km/s Mpc.
|H I 21 centimeter observations and I-band CCD surface photometry of spiral galaxies behind the Virgo Cluster and toward its antipode|
Sample selection, radio and optical data acquisition and reduction, andobservation results are presented for spiral galaxies behind the VirgoCluster and toward its antipode. I-band CCD photometry was obtained forall the bright galaxies and part of the sample of faint galaxies in thetwo local volumes was studied. The statistical properties of the galaxysamples are discussed.
|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.
|Dynamics of Binary Galaxies. I. Wide Pairs|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1993ApJ...419...30C&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.
|The far-infrared properties of the CfA galaxy sample. I - The catalog|
IRAS flux densities are presented for all galaxies in the Center forAstrophysics magnitude-limited sample (mB not greater than 14.5)detected in the IRAS Faint Source Survey (FSS), a total of 1544galaxies. The detection rate in the FSS is slightly larger than in thePSC for the long-wavelength 60- and 100-micron bands, but improves by afactor of about 3 or more for the short wavelength 12- and 25-micronbands. This optically selected sample consists of galaxies which are, onaverage, much less IR-active than galaxies in IR-selected samples. Itpossesses accurate and complete redshift, morphological, and magnitudeinformation, along with observations at other wavelengths.
|Properties and simulations of interacting spiral galaxies with transient 'ocular' shapes|
Computer simulations of interacting galaxies show a transient oval-apexstructure resembling an eye, which sometimes leads to the formation of apermanent central bar. A dimensionless tidal strength parametereffectively distinguishes between the different possible outcomes.Several examples of ocular structure in real galaxies have been found.The rotation curves of ocular galaxies are predicted to have largevelocity irregularities that correspond to distinctive spiral arm anddouble-parallel arm features. The amplitude of the velocity features maybe useful in determining the strength of the tidal interactions.
|A study of the large-scale structure in the distribution of galaxies in a region centered about the Cancer cluster. III - Further observational results|
Further observational results are presented from a study of thelarge-scale structure in the distribution of galaxies in anapproximately 4000 sq deg region nominally centered about the Cancercluster. The criteria used in defining the galaxy sample and theobservational methods used in its study are reviewed. The H I spectraand the associated measured parameters and derived properties for the134 sample galaxies are presented.
|Arecibo H I data for 136 spiral galaxies|
The results of observations of the neutral hydrogen emission of 136spiral galaxies observed using the 21 cm spectral-line system of theArecibo Observatory are presented. Most of the 114 detected objects havebeen mapped along the major axis, and cumulative spectra andposition-velocity contour maps for each of them are presented. The dataare used to determine the overall H I content, systemic velocity, linewidths, and scale-length H I diameters. Data are also presented, indetailed tabular form, for each of the positions observed on thedetected objects.
|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.
|A catalog of hierarchical subclustering in the Turner-Gott groups|
Information on the substructure, to four levels of hierarchy, ispresented for the 103 groups listed by Turner and Gott (TG) in theircatalog of groups of galaxies. All galaxies brighter than Mpg= 14.0 in the region delta is 0 deg or greater and b(II) is 40 deg orgreater that have been assigned group memberships by TG are included.Also listed is the local environmental information for each of thegalaxies, giving the surface density enhancement beta in the galaxy'sneighborhood, calculated at 15 levels in the range beta = 4.6 to 10,000.
|Photographs of nebulae with the 60-inch reflector, 1917-1919.|
|Stars having peculiar spectra. 38 new variables stars.|
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