A normal abundance of faint satellites in the fossil group NGC 6482
Abstract
A fossil group is considered the end product in a galaxy group's evolution. It is a massive central galaxy that dominates the luminosity budget of the group, and is the outcome of efficient merging between intermediate-luminosity members. Little is known, however, about the faint satellite systems of fossil groups. Here we present a Subaru/Suprime-Cam wide-field, deep imaging study in the B - and R -bands of the nearest fossil group NGC 6482 (Mtot ~ 4 × 1012M⊙), covering the virial radius out to 310 kpc. We performed detailed completeness estimations and selected group member candidates by a combination of automated object detection and visual inspection. A fiducial sample of 48 member candidates down to MR ~ -10.5 mag is detected, making this study the deepest of a fossil group to now. We investigate the photometric scaling relations, the color-magnitude relation, and the luminosity function of our galaxy sample. We find evidence of recent and ongoing merger events among bright group galaxies. The color-magnitude relation is comparable to that of nearby galaxy clusters, and it exhibits significant scatter at the faintest luminosities. The completeness-corrected luminosity function is dominated by early-type dwarfs and is characterized by a faint end slope α = -1.32 ± 0.05. We conclude that the NGC 6482 fossil group shows photometric properties consistent with those of regular galaxy clusters and groups, including a normal abundance of faint satellites.
Appendix A is available in electronic form at http://www.aanda.orgThe reduced data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/559/A76- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- November 2013
- DOI:
- 10.1051/0004-6361/201321288
- arXiv:
- arXiv:1309.1166
- Bibcode:
- 2013A&A...559A..76L
- Keywords:
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- galaxies: evolution;
- galaxies: dwarf;
- galaxies: groups: general;
- galaxies: clusters: general;
- galaxies: photometry;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 15 pages, 14 figures, A&