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more about the Ultra-Compact Dwarf companion
Further to previous post regarding the UCD galaxy associated with M104, this UCD was studied by Hau et al., in
2009, MNRAS, volume 394, p.97
(this paper is available as a preprint, at //arxiv.org)
(look for the preprint called....... arxiv: 0901.1693)
They find that the half-light diameter of the UCD is about three times that of one of the biggest "standard globulars" associated with M104.
Their mass estimate for the UCD is 33 million solar masses.
In comparison, the biggest "standard globular clusters" weigh in at 5-10 million solar masses.
Interestingly, they find no requirement for dark matter to hold together this UCD, and to stop it from dispersing. However, in my view, the internal kinematics of this object do need further study so as to confirm this finding.
The only distinguishing factor between the very smallest galaxies and the very largest globulars is often the fact that , by definition, dwarf galaxies would fall apart if it were not for the gravity of the unknown "dark matter".
Oh, and one more thing.......
the total visual (actually V-band) magnitude of the UCD is 17.6
Last edited by madbadgalaxyman; 16-06-2012 at 12:19 AM.
Reason: corrected the maximum of the standard globular cluster mass function
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