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Groups of Galaxies in the Two Micron All Sky Redshift Survey
We present the results of applying a percolation algorithm to theinitial release of the Two Micron All Sky Survey Extended SourceCatalog, using subsequently measured redshifts for almost all of thegalaxies with K<11.25 mag. This group catalog is based on the firstnear-IR all-sky flux-limited survey that is complete to|b|=5deg. We explore the dependence of the clustering on thelength and velocity scales involved. The paper describes a groupcatalog, complete to a limiting redshift of 104 kms-1, created by maximizing the number of groups containingthree or more members. A second catalog is also presented, created byrequiring a minimum density contrast of δρ/ρ>=80 toidentify groups. We identify known nearby clusters in the catalogs andcontrast the groups identified in the two catalogs. We examine andcompare the properties of the determined groups and verify that theresults are consistent with the UZC-SSRS2 and northern CfA redshiftsurvey group catalogs. The all-sky nature of the catalog will allow thedevelopment of a flow-field model based on the density field inferredfrom the estimated cluster masses.
| The 2MASS-selected Flat Galaxy Catalog
An all-sky catalog of 18020 disc-like galaxies is presented. Thegalaxies are selected from the Extended Source Catalog of the Two MicronAll-Sky Survey (XSC 2MASS) basing on their 2MASS axial ratio a/b ≥ 3.The Catalog contains data on magnitudes of a galaxy in the J, H,KS bands, its axial ratio, positional angle, index ofluminosity concentration, as well as identification of the galaxy withthe LEDA and the NED databases. Unlike the available optical catalogs,the new 2MFGC catalog seems to be more suitable to study cosmicstreaming on a scale of z <~ 0.1. The dipole moment of distributionof the bright (K < 11m) 2MFGC objects (l = 227°, b =41° or SGL = 90°, SGB = -43°) lies within statistical errors(±15°) in the direction of the IRAS dipole and the opticalRFGC dipole.
| 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
| 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.
| 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.
| 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.
| Isolated Triplets of Galaxies - a Complete Summary of Radial Velocities and Reduced Data
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