A "friends-of-friends" percolation algorithm has been used to extract a catalog of δn/n = 80 density enhancements (groups) from the six slices of the Las Campanas Redshift Survey (LCRS). The full catalog contains 1495 groups and includes 35% of the LCRS galaxy sample. A clean sample of 394 groups has been derived by culling groups from the full sample that either are too close to a slice edge, have a crossing time greater than a Hubble time, have a corrected velocity dispersion of zero, or contain a 55″ "orphan" (a galaxy with a mock redshift that was excluded from the original LCRS redshift catalog due to its proximity to another galaxy - i.e., within 55″). Median properties derived from the clean sample include a line-of-sight velocity dispersion σlos = 164 km s-1, crossing time tcr = 0.10 H-10, harmonic radius Rh = 0.58 h-1 Mpc, pairwise separation Rp = 0.64 h-1 Mpc, virial mass Mvir = 1.90 × 1013 h-1 M⊙, total group R-band luminosity Ltot = 1.30 × 1011 h-2L⊙, and R-band mass-to-light ratio M/L = 171 h M⊙/L⊙; the median number of observed members in a group is three.
- Galaxies: Clusters: General
- Galaxies: Distances and redshifts
- Large-scale structure of universe
- Surveys on-line material: Machine-readable tables
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science