Satellite galaxies as better tracers of the Milky Way halo mass

Abstract

The inference of the Milky Way halo mass requires modelling the phase space structure of dynamical tracers, with different tracers following different models and having different levels of sensitivity to the halo mass. For steady-state models, phase correlations among tracer particles lead to an irreducible stochastic bias. This bias is small for satellite galaxies and dark matter particles, but as large as a factor of 2 for halo stars. This is consistent with the picture that satellite galaxies closely trace the underlying phase space distribution of dark matter particles, while halo stars are less phase-mixed. As a result, the use of only $\sim 100$ satellite galaxies can achieve a significantly higher accuracy than that achievable with a much larger sample of halo stars.

arXiv commentTo appear in Proceedings of IAU Symposium 353: Galactic Dynamics in the Era of Large Surveys

References in corpus (14)

• A Universal Density Profile from Hierarchical Clustering
• From dwarf spheroidals to cDs: Simulating the galaxy population in a LCDM cosmology
• GAIA: Composition, Formation and Evolution of the Galaxy
• Resolving Cosmic Structure Formation with the Millennium-II Simulation
• The APOSTLE simulations: solutions to the Local Group's cosmic puzzles
• LAMOST Experiment for Galactic Understanding and Exploration (LEGUE) The survey science plan
• HBT+: an improved code for finding subhalos and building merger trees in cosmological simulations
• A unified model for the spatial and mass distribution of subhaloes
• Estimating the dark matter halo mass of our Milky Way using dynamical tracers
• The orbital PDF: general inference of the gravitational potential from steady-state tracers
• What to expect from dynamical modelling of galactic haloes II: the spherical Jeans equation
• The orbital PDF: the dynamical state of Milky Way sized haloes and the intrinsic uncertainty in the determination of their masses
• What to expect from dynamical modelling of galactic haloes
• A Versatile and Accurate Method for Halo Mass Determination from Phase-Space Distribution of Satellite Galaxies

Cited by in corpus (2)

• What to expect from dynamical modelling of cluster haloes I. The information content of different dynamical tracers
• The outermost edges of the Milky Way halo from galaxy kinematics