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Internal Dynamics of the Most Luminous Fornax Cluster UCD

Published online by Cambridge University Press:  11 July 2011

M.J. Frank*
Affiliation:
European Southern Observatory, Garching, Germany Astronomisches Rechen-Institut, Zentrum für Astronomie, Universität Heidelberg, Germany
M. Hilker
Affiliation:
European Southern Observatory, Garching, Germany
S. Mieske
Affiliation:
European Southern Observatory, Vitacura, Santiago, Chile
H. Baumgardt
Affiliation:
School of Mathematics and Physics, University of Queensland, Australia
E.K. Grebel
Affiliation:
Astronomisches Rechen-Institut, Zentrum für Astronomie, Universität Heidelberg, Germany
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Abstract

We present the internal kinematics of UCD3, the brightest known ultra-compact dwarf galaxy (UCD) in the Fornax cluster and the first UCD with spatially resolved spectroscopy. Based on seeing-limited observations with VLT/FLAMES, we measure a velocity field showing the signature of weak rotation and a radial velocity dispersion profile that is flatter than expected from an isotropic Jeans model where mass follows light. We find that both, a strongly anisotropic velocity distribution, and a dark matter component as predicted by simulations of galaxy threshing, can explain the observed flattening.

Type
Research Article
Copyright
© EAS, EDP Sciences, 2011

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References

Mieske, S., Hilker, M., & Infante, L., 2004, A&A, 418, 445
Fellhauer, M., & Kroupa, P., 2002, MNRAS, 330, 642CrossRef
Bekki, K., Couch, W.J., Drinkwater, M.J., & Shioya, Y., 2003, MNRAS, 344, 399CrossRef
Phillipps, S., Drinkwater, M.J., Gregg, M.D., & Jones, J.B., 2001, ApJ, 560, 201CrossRef
Cappellari, M., 2008, MNRAS, 390, 71CrossRef
Hilker, M., Baumgardt, H., Infante, L., et al., 2007, A&A, 463, 119
Goerdt, T., Moore, B., Kazantzidis, S., et al., 2008, MNRAS, 385, 2136CrossRef