Simple dynamical models of the Sagittarius dwarf galaxy

Abstract

We present two simple dynamical models for Sagittarius based on N-body simulations of the progressive disruption of a satellite galaxy orbiting for 12.5 Gyr within a realistic Galactic potential. In both models the satellite initially has observable properties similar to those of current outlying dwarfs; in one case it is purely stellar while in the other it is embedded in an extended massive halo. The purely stellar progenitor is a King model with a total velocity dispersion of 18.9 km/s, a core radius of 0.44 kpc and a tidal radius of 3 kpc. The initial stellar distribution in the other case follows a King profile with the same core radius, a slightly larger total velocity dispersion and similar extent. Both these models are consistent with all published data on the current Sagittarius system, they match not only the observed properties of the main body of Sagittarius, but also those reported for unbound debris at larger distances.

10 pages, 10 figures, MNRAS in press. High resolution Figs.8 and 10 available from http://www.strw.leidenuniv.nl/~ahelmi/sag.html Slight changes in the models, new section added to compare with data outside the main body, analysis of the Sloan results

References in corpus (5)

• Galactic Halo substructure in the Sloan Digital Sky Survey: the ancient tidal stream from the Sagittarius dwarf galaxy
• Candidate RR Lyrae Stars Found in Sloan Digital Sky Survey Commissioning Data
• Constraining the History of the Sagittarius Dwarf Galaxy Using Observations of its Tidal Debris
• The Orbit and Mass of the Sagittarius Dwarf Galaxy
• Starcounts Redivivus: III. A Possible Detection of the Sagittarius Dwarf Spheroidal Galaxy at b=-40

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