J/A+A/342/1 J/A+A/342/1 ESO Slice Project. VI. Groups of Galaxies. M Ramella G Zamorani E Zucca G M Stirpe G Vettolani C Balkowski A Blanchard A Cappi V Cayatte G Chincarini C Collins L Guzzo H MacGillivray D Maccagni S Maurogordato R Merighi M Mignoli A Pisani D Proust R Scaramella Astron. Astrophys. 342 1 1999 1999A&A...342....1R J/A+AS/130/323 : ESO Slice Project (Vettolani+ 1998) Vettolani et al., Paper I. 1997A&A...325..954V Zucca et al., Paper II. 1997A&A...326..477Z Vettolani et al., Paper III. 1998A&AS..130..323V, Cat. <J/A+AS/130/323> Cappi et al., Paper IV. 1998A&A...336..445C Scaramella et al. Paper V. 1998A&A...334..404S Clusters, galaxy Radial velocities Velocity dispersion cosmology: observations galaxies: clusters: general galaxies: distances and redshifts large-scale structure of universe In Table 1 we present our group catalog. For each group we list the ID number (column 1), the number of members (column 2), the coordinates {alpha}_(1950)_ and {delta}_(1950)_ (columns 3 and 4 respectively), the mean radial velocity cz in km/s corrected for Virgo infall and galactic rotation (column 5), and the velocity dispersion {sigma}_cz_ (column 6). We compute the velocity dispersion following the prescription of Ledermann (1984) for an unbiased estimator of the dispersion (see previous section). We also take into account the cosmological expansion of the universe and the measurement errors according to the prescriptions of Danese et al. (1980A&A....82..322D). The errors we associate to the redshifts are those output by the RVSAO cross-correlation procedure multiplied by a factor 1.6. This factor brings the cross-correlation error in rough agreement with the external error estimated from repeated observations (Vettolani et al., 1998, Cat. <J/A+AS/130/323> -- here we do not distinguish between emission and absorption line redshifts).

Groups Groups identification number --- Nmem Number of members --- RAh Right ascension (1950) h RAm Right ascension (1950) min RAs Right ascension (1950) s DE- Declination sign --- DEd Declination (1950) deg DEm Declination (1950) arcmin DEs Declination (1950) arcsec cz Mean radial velocity km/s l_sigma limit flag on sigma number=1 In the case of 24 groups, the correction of {sigma}_cz_ for the measurement errors leads to a negative value. The error is given as an upper limit to {sigma}_cz_ for these groups. --- sigma Velocity dispersion km/s Nocz Ratio of galaxies that have not a measured redshift to the number of members number=2 Not all galaxies in the region of the sky covered by the ESP survey have a measured redshift. Of the original target list, 444 objects are not observed, and 207 objects have a noisy spectrum, insufficient for a reliable determination of the redshift. Nocz value gives, for each group, the ratio of these objects to the number of members. --- table1.psPostScript version of table1 table1.texLaTeX version of table1 Patricia Bauer CDS 1998Nov16Massimo Ramella <ramella@suw003.oat.ts.astro.it> J_A+A_342_1.xml