The Galaxy Luminosity Functions down to M ~ -10 in the Hydra I Cluster
Abstract
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 RC 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.
- Publication:
-
The Astronomical Journal
- Pub Date:
- July 2007
- DOI:
- 10.1086/518475
- arXiv:
- arXiv:astro-ph/0701670
- Bibcode:
- 2007AJ....134...56Y
- Keywords:
-
- galaxies: clusters: individual: Hydra I;
- galaxies: dwarf;
- galaxies: luminosity function;
- mass function;
- Astrophysics
- E-Print:
- 21 pages, 6 figures, submitted to AJ