1997/11/30 by Roberto Trasarti-Battistoni, R. Trasarti–Battistoni · 3 citations
Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1051/aas:1998229
18 pages, including 9 .eps figures (uses aa.cls and epsf.sty). The group catalog presented here will be available via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or http://cdsweb.u-strasbg.fr/CDS.html Upon request, the author can provide other group catalogs in electronic form Final version, to be published in A&A Suppl. Minor changes in the discussion of D_L vs dn/n, references updated, figures encapsulated in the paper
arxiv created 1998/01/09 · openalex publication_date 1998/06/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
We present a large catalog of loose groups of galaxies in the Southern Galactic Hemisphere, selected from the Perseus–Pisces redshift Survey (PPS). Particular care is taken in order to obtain group samples as homogeneous as possible to previously published catalogs. All our catalogs contain about 200 groups, significantly more than in most previous studies where group samples were obtained from galaxy data sets of comparable quality to (but smaller extent than) PPS. Groups are identified with the adaptive Friends–Of–Friends (FOF) algorithm of Huchra & Geller (1982), with suitable normalizations and at . The luminosity function (LF) normalization appropriate for PPS yields a number density threshold for the adopted D0, instead of used in previous studies of other samples. However, the customary choice of D0 obtained (through the LF) from a fixed mass overdensity , well motivated in theory, suffers from important observational uncertainties and sample–to–sample variations of the LF normalization, and from major uncertainties in the relation between galaxy density n and mass density ρ . We discuss how to self–consistently match FOF parameters among different galaxy samples. We then separately vary several FOF and sample parameters, and discuss their effect on group properties. Loose groups in PPS nicely trace the large scale structure (LSS) in the parent galaxy sample. The group properties vary little with different redshift corrections, redshift cut–off, and galaxy LF, but are rather sensitive to the adopted links D0 and V0. More precisely, the typical group size (velocity dispersion) is linearly related to the adopted distance (velocity) link, while it is rather insensitive to the adopted velocity (distance) link. Physical properties of groups in PPS and in directly comparable samples show good agreement. There is a complex interplay among LSS features, sample depth, FOF grouping procedure, and group properties.