Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2011-03-24
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
12 pages, 15 figures. Accepted for publication in A&A. Abstract has been abridged for astroph
Scientific paper
In the last decade, extended stellar clusters with masses in the range from a few 10^4 to 10^8 M_sun have been found in various types of galaxies in different environments. Objects with masses comparable to normal globular clusters (GCs) are called extended clusters (ECs), while objects with masses in the dwarf galaxy regime are called ultra-compact dwarf galaxies (UCDs). In heavily interacting galaxies star clusters tend to form in larger conglomerations called star cluster complexes (CCs). In this work we systematically scan a suitable parameter space for CCs and perform numerical simulations to study their further fate. The varied sizes and masses of the CCs cover a matrix of 5x6 values with CC Plummer radii between 10 - 160 pc and CC masses between 10^5.5 - 10^8 M_sun, which are consistent with observed CC parameters. The CCs of the parametric study are on orbits with distances between 20 kpc and 60 kpc. In addition, we studied also the evolution of CCs on a circular orbit at a distance of 60 kpc to verify that also extremely extended ECs and UCDs can be explained by our formation scenario. All 54 simulations end up with stable merger objects, wherein 26 to 97% of the initial CC mass is bound. The objects show a general trend of increasing effective radii with increasing mass. Despite the large range of input Plummer radii of the CCs (10 to 160 pc) the effective radii of the merger objects are constrained to values between 10 and 20 pc at the low mass end and to values between 15 and 55 pc at the high mass end. The structural parameters of the models are comparable to those of the observed ECs and UCDs. The results of the circular orbits demonstrate that even very extended objects like the M31 ECs found by Huxor in 2005 and the very extended (r_eff > 80 pc), high-mass UCDs can be explained by merged cluster complexes in regions with low gravitational fields at large distances.
Assmann Patrick
Bruens R. C.
Fellhauer Michael
Kroupa Pavel
Metz Manuel
No associations
LandOfFree
A parametric study on the formation of extended star clusters and ultra-compact dwarf galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A parametric study on the formation of extended star clusters and ultra-compact dwarf galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A parametric study on the formation of extended star clusters and ultra-compact dwarf galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-49097