1998/08/05 by Daniel Koranyi, Daniel M. Koranyi, Margaret J. Geller +4 · 3 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Scientific Research and Discoveries #astro-ph
paper · pdf · doi:10.1086/300611
37 pages, LaTeX, including 12 Figures and 1 Table. Accepted for publication in the Astronomical Journal
arxiv created 1998/08/05 · openalex publication_date 1998/11/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
We have measured redshifts and Kron-Cousins R -band magnitudes for a sample of galaxies in the poor cluster AWM 7. We have measured redshifts for 172 galaxies; 106 of these are cluster members. We determine the luminosity function (LF) from a photometric survey of the central 1.2 × 1.2 h -1 Mpc. The LF has a bump at the bright end and a faint-end slope of α = -1.37 ± 0.16, populated almost exclusively by absorption-line galaxies. The cluster velocity dispersion is lower in the core (∼530 km s -1 ) than at the outskirts (∼680 km s -1 ), consistent with the cooling flow seen in the X-ray. The cold core extends ∼150 h -1 kpc from the cluster center. The Kron-Cousins R -band mass-to-light ratio of the system is 650 ± 170 h M ⊙ / L ⊙ , substantially lower than previous optical determinations, but consistent with most previous X-ray determinations. We adopt H 0 = 100 h km s -1 Mpc -1 throughout this paper; at the mean cluster redshift (5247 ± 76 km s -1 ), 1 h -1 Mpc subtends 65 5.