The specific globular cluster frequencies of dwarf elliptical galaxies from the Hubble Space Telescope

Citation
Bw. Miller et al., The specific globular cluster frequencies of dwarf elliptical galaxies from the Hubble Space Telescope, ASTROPHYS J, 508(2), 1998, pp. L133-L137
Citations number
25
Categorie Soggetti
Space Sciences
Journal title
ASTROPHYSICAL JOURNAL
ISSN journal
0004637X → ACNP
Volume
508
Issue
2
Year of publication
1998
Part
2
Pages
L133 - L137
Database
ISI
SICI code
0004-637X(199812)508:2<L133:TSGCFO>2.0.ZU;2-E
Abstract
The specific globular cluster frequencies (S-N) for 24 dwarf elliptical (dE ) galaxies in the Virgo and Fornax Clusters and the Leo Group that were ima ged with the Hubble Space Telescope are presented. Combining all available data, we find that for nucleated dE (dE, N) galaxies, which are spatially d istributed like giant elliptical galaxies in galaxy clusters, (S) over bar( N)(dE, N) = 6.5 +/- 1.2 and S-N increases with M-V, while for nonnucleated dE (dE, noN) galaxies, which are distributed like late-type galaxies, (S) o ver bar(N)(dE, noN) = 3.1 +/- 0.5 and there is little or no trend with M-V. Thus, the S-N values for dE galaxies are, on average, significantly higher than those for late-type galaxies, which have S-N less than or similar to 1. This suggests that dE galaxies are more akin to giant elliptical galaxie s than to late-type galaxies. If there are dormant or stripped irregular ga laxies hiding among the dE population, they are likely to be among the nonn ucleated dE galaxies. Furthermore, the similarities in the properties of th e globular clusters (GCs) and in the spatial distributions of dE, N galaxie s and giant elliptical galaxies suggest that neither galaxy mass nor galaxy metallicity is responsible for the high values of S-N. Instead, most metal -poor GCs may have formed in dwarf-sized fragments that merged into larger galaxies.