English

On Kinematic Substructure in the Sextans Dwarf Spheroidal Galaxy

Astrophysics 2009-11-11 v1

Abstract

We present multifiber echelle radial velocity results for 551 stars in the Sextans dwarf spheroidal galaxy and identify 294 stars as probable Sextans members. The projected velocity dispersion profile of the binned data remains flat to a maximum angular radius of 3030^{\prime}. We introduce a nonparametric technique for estimating the projected velocity dispersion surface, and use this to search for kinematic substructure. Our data do not confirm previous reports of a kinematically distinct stellar population at the Sextans center. Instead we detect a region near the Sextans core radius that is kinematically colder than the overall Sextans sample with 95% confidence.

Keywords

Cite

@article{arxiv.astro-ph/0603694,
  title  = {On Kinematic Substructure in the Sextans Dwarf Spheroidal Galaxy},
  author = {Matthew G. Walker and Mario Mateo and Edward W. Olszewski and Jayanta Kumar Pal and Bodhisattva Sen and Michael Woodroofe},
  journal= {arXiv preprint arXiv:astro-ph/0603694},
  year   = {2009}
}

Comments

accepted for publication in ApJ Letters; 4 figures (2 color)