Journal
ASTRONOMICAL JOURNAL
Volume 127, Issue 5, Pages 2674-2693Publisher
IOP PUBLISHING LTD
DOI: 10.1086/383297
Keywords
galaxies : dwarf; galaxies : spiral; galaxies : star clusters
Categories
Ask authors/readers for more resources
We use CTIO 4 m Mosaic II images taken with the Washington CM and Harris R filters to identify candidate globular clusters in the six major galaxies of the Sculptor group: NGC 45, 55, 247, 254, 300, and 7793. From follow-up spectroscopy with Hydra-CTIO, we find 19 new globular clusters in NGC 55, 247, 253, and 300, bringing the total number of known Sculptor group globular clusters to 36. The newly discovered clusters have spectroscopic ages consistent with those of old Milky Way globular clusters, and the majority are metal-poor. Their luminosity function closely resembles that of the Milky Way's globular clusters; their metallicity distribution is somewhat more metal-rich, but this may be the result of our color selection of candidates. The mean [alpha/Fe] ratio in the clusters is - 0.2 +/- 0.3, which is lower than the Milky Way average. The specific frequencies S(N) are similar to those of other late-type galaxies. However, if we calculate the specific frequency using the K-band total magnitudes of the host galaxies, we find values that are more than a factor of 2 higher. The kinematics of the globular cluster systems are consistent with rotation with the H I disk in each of the four galaxies; however, only in NGC 253 is this result based on more than seven objects. We suggest that the Sculptor group galaxies add to evidence indicating that many of the first-generation globular clusters formed in disks, not halos.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available