J. M. Diederik Kruijssen, Andrew P. Cooper
We test whether the masses of old globular clusters (GCs) in dwarf galaxies
are consistent with the same initial mass spectrum as young massive clusters
(YMCs) in nearby star-forming galaxies. The most massive GCs of dwarf galaxies
are compared to their expected masses when drawing from the Schechter-type ICMF
of YMCs. It is found that the most massive GCs of galaxies in the stellar mass
range M_*,gal=10^7-10^9 Msun are consistent with the same initial mass spectrum
as YMCs in about 90% of the cases, suggesting that their formation mechanisms
were the same. For the remaining 10%, the most massive clusters are nuclear
GCs, which have been able to grow to higher masses through further merging
after their initial formation ended. Because the effects of cluster disruption
are weaker for more massive clusters, we estimate that up to one third of the
metal-poor GCs in the Milky Way may have a nuclear origin, while the remaining
two thirds formed through the same process as YMCs in the local universe. A
log-normal ICMF is inconsistent with observed GCs at a 99.6% confidence level.
View original:
http://arxiv.org/abs/1110.4106
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