2007/01/24 by H. Yamanoi, Hitomi Yamanoi, Masayuki Tanaka +17 · 1 citation
Physics and Astronomy · #Astronomy #Astrophysics #Cluster (spacecraft) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Gamma-ray bursts and supernovae #Geography #Lernaean Hydra #Luminosity #Luminosity function #Photometry (optics) #Physics #Population #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/518475
published as Astron.J.134:56-63,2007 · 21 pages, 6 figures, submitted to AJ
arxiv created 2007/01/24 · openalex publication_date 2007/05/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study the galaxy population of the Hydra I cluster in the central region and a region about 0.6 Mpc away from its center in the B and R C bands down to M ∼ -10 using Subaru Suprime-Cam photometry. We find that the luminosity function of the entire population has a slightly steeper slope (α ∼ -1.6) in the range of -20 < M < -10 than those reported for other clusters in slightly brighter ranges. The slope appears to be steeper in poorer clusters. The number of faint galaxies ( M > -14) increases in the cluster center, as well as in bright galaxies. The Hydra I cluster is dominated by red dwarfs, and the luminosity function shows a significant upturn at M ∼ -16, as is seen in several other nearby clusters but not in the field. This upturn and the variation in the faint-end slope of the luminosity function may be caused by the cluster environment or the evolution history of individual clusters.