The relative average minimum projected separations of star clusters in the Legacy ExtraGalactic UV Survey (LEGUS) and in tidal dwarfs around the interacting galaxy NGC 5291 are determined as a function of cluster mass to look for cluster-cluster mass segregation. Class 2 and 3 LEGUS clusters, which have a more irregular internal structure than the compact and symmetric class 1 clusters, are found to be mass-segregated in low-mass galaxies, which means that the more massive clusters are systematically bunched together compared to the lower-mass clusters. This mass segregation is not present in high-mass galaxies or class 1 clusters. We consider possible causes for this segregation, including differences in cluster formation and scattering in the shallow gravitational potentials of low-mass galaxies.
The Astrophysical Journal
- Pub Date:
- January 2020
- Star formation;
- Star clusters;
- Astrophysics - Astrophysics of Galaxies
- accepted for ApJ Letters, 10 pages, 4 figures