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Gas and Stars in an H I-Selected Galaxy Sample
We present the results of a J-band study of the H I-selected AreciboDual-Beam Survey and Arecibo Slice Survey galaxy samples using TwoMicron All Sky Survey data. We find that these galaxies span a widerange of stellar and gas properties. However, despite the diversitywithin the samples, we find a very tight correlation between luminosityand size in the J band, similar to that found in a previous paper byRosenberg & Schneider between the H I mass and size. We also findthat the correlation between the baryonic mass and the J-band diameteris even tighter than that between the baryonic mass and the rotationalvelocity.
| 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
| 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.
| A Deep Survey of H I-selected Galaxies: The Sample and the Data
In a 21 cm neutral hydrogen survey of approximately 55 deg^2 out to aredshift of cz = 8340 km s^-1, we have identified 75 extragalactic H Isources. These objects comprise a well-defined sample of extragalacticsources chosen by means that are independent of optical surfacebrightness selection effects. In this paper we describe the Arecibosurvey procedures and H I data, follow-up VLA H I observations made ofseveral unusual sources, and Kitt Peak B-, R-, and I-band photometry fornearly all of the galaxies. We have also gathered information for someof the optically detected galaxies within the same search volume. Weexamine how samples generated by different types of search techniquesoverlap with selection by H I flux. Only the least massive H I object,which is among the lowest mass H I sources previously found, does nothave a clear optical counterpart, but a nearby bright star may hide lowsurface brightness emission. However, the newly detected systems do haveunusual optical properties. Most of the 40 galaxies that were notpreviously identified in magnitude-limited catalogs appear to begas-dominated systems, and several of these systems have H Imass-to-light ratios among the largest values ever previously found.These gas-dominated objects also tend to have very blue colors, lowsurface brightnesses, and no central bulges, which correlate stronglywith their relative star-to-gas content.
| 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.
| Hot HB stars in globular clusters: physical parameters and consequences for theory. II. NGC 6397 and its short blue horizontal branch.
New visual spectra of 14 blue horizontal-branch (BHB) stars in NGC 6397and 2 spectra from the literature are used to derive atmosphericparameters (T_eff_, logg) for these stars. With the theoretical surfacebrightness for the derived stellar parameters and with the givendistance of the cluster one then can calculate the radius, theluminosity, and the mass of the BHB stars. Low dispersion IUE spectrahave been obtained of 7 BHB stars and these are used together withvisual data to determine the integrated flux of the stars directly fromthe spectrophotometry. This allows, using the distance, to calculate theluminosity leading to an additional determination of the mass of the BHBstars. The overall observed spectral energy distribution of the stars(visual and IUE data) is compared with atmosphere models for metal-poorstars. The models are somewhat too bright at λ<1500A and toofaint in the 2500A range. Our data indicate, that the BHB stars have amass ranging from 0.3Msun_ to 0.7Msun_ (with amean of 0.4Msun_) over the temperature range of 8800 to12000K. These masses are smaller than those from classical single starevolution. Implications of the results are discussed, including problemswith the cluster distance modulus, the gravities, problems with thetheoretical Balmer profiles, and possibly more complicated origins forthe HBB stars.
| Survey of emission-line galaxies: Universidad Complutense de Madrid list
A low-dispersion objective-prism survey for low-redshift emission-linegalaxies (ELGs) is being carried out by the University Complutense deMadrid with the Schmidt telescope at the German-Spanish Observatory ofCalar Alto (Almeria, Spain). A 4 deg full aperture prism, which providesa dispersion of 1950 A/mm, and IIIaF emulsion combination has been usedto search for ELGs selected by the presence of H-alpha emission in theirspectra. Our survey has proved to be able to recover objects alreadyfound by similar surveys with different techniques and, what is moreimportant, to discover new objects not previously cataloged. Acompilation of descriptions and positions, along with finding chartswhen necessary, is presented for 160 extragalactic emission-lineobjects. This is the first list, which contains objects located in aregion of the sky covering 270 sq deg in 10 fields near alpha =0h and delta = 20 deg.
| The classification of globular clusters by means of cluster analysis
The distributions of globular clusters in the spaces of basic physicalparameters are considered using a cluster analysis method. The Euclideandistance between clusters in the corresponding space is used as thesimilarity measure. Several classification variants are proposed; insome cases, it is due to the dependence of the cluster properties on thedistance from the Galactic center. The classes identified are notisolated but go from one to another continuously.
| Large-scale structure of the Hercules supercluster.
Not Available
| A VLA 20 CM survey of poor groups of galaxies
The paper reports on VLA 20 cm observations of an extensive sample ofgalaxies in 139 poor groups. These groups, composed of galaxies down tothe limit of the Zwicky et al. (CGCG) catalog, were chosen using apercolation algorithm set at a high surface-density threshold.Approximately 50 percent of the groups have measured redshifts. Thesegroups were surveyed using a 'snapshot' mode of the VLA with aresolution of about 13 arcsec. Analysis of the resulting radio andoptical properties reveals that the presence of a nearby companiongalaxy has an important role in generating radio emission in a galaxy.CCD observations of two radio-loud, disturbed galaxies with companionsare presented and are used to discuss models of radio-source production.Nine tailed radio galaxies are found in the poor groups, which is muchmore than had been expected from previous work on rich clusters and fromtheoretical models. The paper discusses previous statistical biases andproposes a method for bending head-tail sources in poor groups. From theconfinement of extended radio features associated with tailed sources,the presence of a substantial intracluster medium that should radiatesignificantly at soft-X-ray energies is predicted.
| A 21 CM survey of the Pisces-Perseus supercluster. II - The declination zone +21.5 to +27.5 degrees
Neutral-hydrogen 21-cm line spectra and derived parameters are presentedfor a sample of spiral galaxies in the region bounded by an R.A. greaterthan 22 h and less then 0.04 h, and a declination greater than +21 deg30 min and less than +27 deg 30 min, covering the Zwicky fields 470 to488, as the second installment of a survey of the region of thePisces-Perseus supercluster. New H I line observations made with theArecibo 305 m telescope detected 275 galaxies of 318 studied. Atabulation of derived galaxian properties is given. The redshiftdistribution shows gross departures from that expected for a sample withsimilar magnitude characteristics but homogeneously located in space.These new data will be incorporated into the overall survey of thethree-dimensional structure in the Pisces-Perseus region.
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