Galaxy And Mass Assembly (GAMA): The Merging Potential of Brightest Group Galaxies
Abstract
Using a volume-limited sample of 550 groups from the Galaxy And Mass Assembly Galaxy Group Catalogue spanning the halo mass range $12.8\lt \mathrm{log}[{M}_{h}/{M}_{\odot }]\lt 14.2$ , we investigate the merging potential of central Brightest Group Galaxies (BGGs). We use spectroscopically confirmed close-companion galaxies as an indication of the potential stellar mass buildup of low-redshift BGGs, z ≤ 0.2. We identify 17 close-companion galaxies with projected separations rp < 30 kpc, relative velocities Δv ≤ 300 km s-1, and stellar mass ratios MBGG/MCC ≤ 4 relative to the BGG. These close-companion galaxies yield a total pair fraction of 0.03 ± 0.01. Overall, we find that BGGs in our sample have the potential to grow in stellar mass due to mergers by 2.2 ± 1.5% Gyr-1. This is lower than the stellar mass growth predicted by current galaxy evolution models.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 2021
- DOI:
- 10.3847/1538-4357/ac1c0a
- arXiv:
- arXiv:2108.05923
- Bibcode:
- 2021ApJ...921...47B
- Keywords:
-
- Galaxy evolution;
- Galaxy groups;
- Early-type galaxies;
- 594;
- 597;
- 429;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 12 pages, 7 figures, Accepted for publication by ApJ