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Measuring Stellar Velocity Dispersions in Active Galaxies
We present stellar velocity dispersion (σ*)measurements for a significant sample of 40 broad-line (type 1) activegalaxies for use in testing the well-known relation black hole mass andstellar velocity dispersion. The objects are selected to contain Ca IItriplet, Mg I b triplet, and Ca H+K stellar absorption features in theiroptical spectra so that we may use them to perform extensive tests ofthe systematic biases introduced by both template mismatch andcontamination from the active galactic nucleus (AGN). We use the Ca IItriplet as a benchmark to evaluate the utility of the other spectralregions in the presence of AGN contamination. Broad Fe II emission,extending from ~5050 to 5520 Å, in combination with narrow coronalemission lines, can seriously bias σ* measurements fromthe Mg I b region, highlighting the need for extreme caution in its use.However, we argue that at luminosities constituting a moderate fractionof the Eddington limit, when the Fe II lines are both weak and smoothrelative to the stellar lines, it is possible to derive meaningfulmeasurements with careful selection of the fitting region. Inparticular, to avoid the contamination of coronal lines, we advocate theuse of the region 5250-5820 Å, which is rich in Fe absorptionfeatures. At higher AGN contaminations, the Ca H+K region may providethe only recourse for estimating σ*. These features arenotoriously unreliable, due to a strong dependence on spectral type, asteep local continuum, and large intrinsic broadening. Indeed, we find astrong systematic trend in comparisons of Ca H+K with other spectralregions. Luckily the offset is well described by a simple linear fit asa function of σ*, which enables us to remove the biasand thus extract unbiased σ* measurements from thisregion. We lay the groundwork for an extensive comparison between blackhole mass and bulge velocity dispersion in active galaxies, as describedin a companion paper by Greene & Ho.
| 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.
| Compact groups in the UZC galaxy sample
Applying an automatic neighbour search algorithm to the 3D UZC galaxycatalogue (Falco et al. \cite{Falco}) we have identified 291 compactgroups (CGs) with radial velocity between 1000 and 10 000 kms-1. The sample is analysed to investigate whether Tripletsdisplay kinematical and morphological characteristics similar to higherorder CGs (Multiplets). It is found that Triplets constitute lowvelocity dispersion structures, have a gas-rich galaxy population andare typically retrieved in sparse environments. Conversely Multipletsshow higher velocity dispersion, include few gas-rich members and aregenerally embedded structures. Evidence hence emerges indicating thatTriplets and Multiplets, though sharing a common scale, correspond todifferent galaxy systems. Triplets are typically field structures whilstMultiplets are mainly subclumps (either temporarily projected orcollapsing) within larger structures. Simulations show that selectioneffects can only partially account for differences, but significantcontamination of Triplets by field galaxy interlopers could eventuallyinduce the observed dependences on multiplicity. Tables 1 and 2 are onlyavailable in electronic at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.125.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/391/35
| 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.
| Accurate Positions for MCG Galaxies
We have measured accurate celestial coordinates for 4741 extragalacticobjects, primarily drawn from a list of MCG galaxies with no recentlypublished accurate positions. The standard deviations in the newpositions depend slightly on the measurement method but are on the orderof 1.0" to 1.2". Standard deviations in the original MCG positions areconfirmed to be at the 1.5′-2.0′ level. These new positionswere integrated into NED in 1997 December.
| Groups of galaxies. III. Some empirical characteristics.
Not Available
| 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
| 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 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.
| Emission-line galaxies in the third list of the Case Low-Dispersion Northern Sky Survey
Observations of 47 galaxies in the third Case list are reported.Thirty-five of the galaxies in the sample were selected for the presenceof emission lines on the objective prism plates. At the higher spectraldispersion of the data, significant line emission was found in 46 of the47 galaxies. Twenty-six galaxies are found to be undergoing significantbursts of star formation. Ten additional galaxies may be starburstgalaxies with low-excitation spectra. Two galaxies are probably typeSeyfert 2. The most distant object, CG 200, at a redshift of 0.144, hasa strong broad H-alpha emission line, and is probably a Seyfert 1.Seventeen of the galaxies have been detected by IRAS. Eight of the IRASgalaxies have H-II-region-type spectra and eight have low-ionizationstarburst spectra. The galaxies represent a mixture of types, rangingfrom intrinsically faint dwarf galaxies with Mb equalling -16 mag, topowerful galaxies with MB equalling -23 mag. Galaxies CG 234 and CG 235are interacting, as are galaxies CG 269 and CG 270.
| HI observations of galaxies in nearby Zwicky clusters
The results of a long term project of H I observations of galaxieswithin the boundaries of nearby Zwicky clusters are presented. Thedetection rate is rather low (233 out of 618, i.e., 38 percent) ascompared to other surveys carried out recently. Most of the radialvelocities of the detected galaxies are new determinations. The largespread in radial velocities for many of these clusters is a strongindication for the presence of several foreground and/or backgroundgalaxies.
| KISO survey for ultraviolet-excess galaxies. XI
Charts of UV-excess galaxies detected on multicolor plates with the KisoSchmidt telescope are presented. A total of 10 survey field areconsidered. In a 300-sq-deg sky area, 460 objects are cataloged to aphotographic magnitude of about 18.
| A deep redshift survey of IRAS galaxies towards the Bootes void
Redshifts were measured for a complete sample of galaxies detected bythe IRAS within 11.5 deg of the center of the void in Bootes discoveredby Kirshner et al (1981). There are 12 IRAS galaxies within the void asdefined by the above authors, seven of which were discovered in thissurvey. One of these has a companion at the same redshift. The resultingdensity of IRAS galaxies in the void is measured to be between 1/6 and1/3 of the average density; the uncertainty is dominated by Poissonstatistics. Good agreement is found between the selection function andnumber density derived from the present sample and those derived fromthe all-sky sample of Strauss (1989). The optical spectra of the newlyfound galaxies in the void are typical of IRAS galaxies in the field.
| Spectra of galaxies in the Case Low-Dispersion Sky Survey in the direction of the Bootes void
A sample of 34 galaxies selected from the Case Low-Dispersion NorthernSky Survey in the direction of the Bootes void. Emission-line redshiftswere obtained for 33 objects; the spectrum of the thirty-fourth galaxycontains no obvious features. Three of the emission-line galaxies arelcoated within the boundaries of the Bootes void, including one notpreviously reported. To date, all the galaxies discovered in the voidhave emission-line spectra. Although more than half the galaxies in thesample are fainter than M(B) = -21.0 mag, all five of the galaxies thatwere detected by IRAS are brighter than M(B) = 21.5 mag. The relativestrengths of the emission lines in most of the galaxies, including thosein the void, indicate the lines are excited by photoionization due toyoung, hot O and B stars. Possible causes for the star formationoccurring in these galaxies include interaction with nearby galaxies,star formation induced by nuclear activity, and/or recent development ofphysical conditions required for star formation.
| The case low-dispersion northern sky survey. IV - Galaxies in the Bootes void region
Positions, estimated magnitudes, and finding charts (when needed) areprovided for 424 blue and/or emission-line galaxies and 50 probable H IIregions in 21 galaxies contained within the region R.A. between 14 h 00m and 15 h 30 m and decl. between +33.0 deg and +56.0 deg (1950). Thesewere identified on low-dispersion, objective-prism plates taken with theBurrell Schmidt-type telescope at Kitt Peak. This sample, which includesgalaxies as faint as the 18th blue magnitude, should prove useful infurther studies of the Bootes void.
| A redshift survey of IRAS galaxies in the Bootes void area
Results of a redshift survey of IRAS galaxies in a 73 deg-squared regioncovering about 1/6 of the Bootes void area are presented. None of the 22newly observed IRAS galaxies are located within this void. The 60-micronluminosity function obtained from these data and those of Vader andSimon (1987) is in good agreement with previous determinations.
| A search for environmental effects on the optical properties of galaxies in groups
Environmental density-related modifications of basic optical properties(luminosities, sizes, axial ratios, and colors) of galaxies belonging toGeller and Huchra's (1983) groups have been investigated. Remarkably, itis found that the broad maxima of the distributions of luminosities anddiameters of spirals and the whole corresponding distributions oflenticulars tend to move to lower values as one goes to groups of highcompactness, whereas the luminosity-diameter relationship of spiralstends to become flatter. No color and axial ratio differences betweengalaxies of high- and low-compactness groups have been detected.
| 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.
| 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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