2004/09/03 by J. T. Kleyna, Jan Kleyna, M. I. Wilkinson +3 · 6 citations
Physics and Astronomy · #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2004.08434.x
7 pages, 9 figures, accepted for publication in MNRAS
arxiv created 2004/09/03 · openalex publication_date 2004/11/04 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present the line-of-sight radial velocity dispersion profile of the Sextans dwarf spheroidal galaxy (dSph), based on a sample of 88 stars extending to about 1° (∼1.5 kpc). Like the Draco and Ursa Minor dSphs, Sextans shows some evidence of a fall-off in the velocity dispersion at large projected radii, with significance p= 0.96. Surprisingly, the dispersion at the very centre of Sextans is close to zero (with significance p= 0.96). We present evidence which suggests that this latter change in the stellar kinematics coincides with changes in the stellar populations within the dSph. We discuss possible scenarios which could lead to a kinematically and photometrically distinct population at the centre of Sextans.