A&A 437, 383-388 (2005)
DOI: 10.1051/0004-6361:20052675
Are great disks defined by satellite galaxies in Milky-Way type halos rare
in
CDM?
X. Kang1, S. Mao2, L. Gao3 and Y. P. Jing1 1 Shanghai Astronomical Observatory; the Partner Group of MPA, Nandan Road 80, Shanghai 200030, PR China
e-mail: kangx@shao.ac.cn
2 University of Manchester, Jodrell Bank Observatory, Macclesfield, Cheshire SK11 9DL, UK
3 Max-Planck Institute for Astrophysics, Karl-Schwarzschild-strasse 1, Garching 85748, Germany
(Received 17 January 2005 / Accepted 2 March 2005 )
Abstract
We study the spatial distribution of satellite galaxies
by assuming that they follow the dark matter distribution. This
assumption is supported by semi-analytical studies based on
high-resolution numerical simulations. We find that for a
Milky-Way type halo, if only a dozen satellite galaxies are
observed, then they can lie on a "great" disk with an rms height
of about 40 kpc. The normal to the plane is roughly isotropic on
the sky. These results are consistent with the observed properties
of the satellite galaxies in the Milky Way. If, however, the
satellite galaxies follow the distribution of substructure
selected by the present mass, then great disks similar to the one in the
Milky Way will be rare and difficult to reproduce, in agreement with
the conclusion reached by Kroupa et al. (2004).
Key words: Galaxy: evolution -- Galaxy: halo -- galaxies: dwarf -- galaxies: structure
© ESO 2005

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