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: http://www.stsci.edu/~marel/abstracts/abs_A3.html
Дата изменения: Mon Dec 18 19:01:56 2000 Дата индексирования: Tue Oct 2 08:49:31 2012 Кодировка: Поисковые слова: universe |
To interpret this observation we construct dynamical models based on the Jeans equation for a spherical system. The light distribution of the cluster is modeled using an isophotal analysis of an HST V-band image from the HST Data Archive, combined with new ground-based K-band imaging. Under the assumption of an isotropic velocity distribution, the observed kinematics imply a K-band mass-to-light ratio M/L_K = 0.05, and a cluster mass M ~ 6 million solar masses. We model the mass-to-light ratio with the `starburst99' stellar population synthesis models of Leitherer and collaborators, and infer a best-fitting cluster age in the range 63-630 Myears. Although this result depends somewhat on a number of uncertainties in the modeling (e.g., the assumed extinction along the line-of-sight towards the nucleus, the IMF of the stellar population model, and the velocity dispersion anisotropy of the cluster), none of these can be plausibly modified to yield a significantly larger age. We will discuss the implications of this result on scenarios of cluster formation in the nuclei of spiral galaxies.
As a byproduct of our analysis, we infer that IC 342 cannot have any
central black hole more massive than 0.5 million solar masses. This is
~ 6 times less massive than the black hole inferred to exist in our
Galaxy, consistent with the accumulating evidence that galaxies with
less massive bulges harbor less massive black holes.