Dark matter distribution and dynamics of dwarf spheroidal galaxies

Abstract

I review the current status of dynamical modelling of dwarf spheroidal galaxies focusing on estimates of their dark matter content. Starting with the simplest methods using the velocity dispersion profiles I discuss the inherent issues of mass-anisotropy degeneracy and contamination by unbound stars. I then move on to methods of increasing complexity, aiming to break the degeneracy, up to recent applications of the Schwarzschild orbit superposition method. The dynamical modelling is placed in the context of possible scenarios for the formation of dwarf spheroidal galaxies, including the tidal stirring model and mergers of dwarf galaxies. The two scenarios are illustrated with examples from simulations: a comparison between the tidal evolution of dwarfs with cuspy and cored dark matter profiles and the formation of a dwarf spheroidal with prolate rotation.

arXiv comment8 pages, 3 figures, invited review for the IAU Symposium 353 "Galactic Dynamics in the Era of Large Surveys"

References in corpus (27)

• The Metamorphosis of Tidally Stirred Dwarf Galaxies
• On the Efficiency of the Tidal Stirring Mechanism for the Origin of Dwarf Spheroidals: Dependence on the Orbital and Structural Parameters of the Progenitor Disky Dwarfs
• Dark matter distribution in dwarf spheroidal galaxies
• The mass and velocity anisotropy of the Carina, Fornax, Sculptor and Sextans dwarf spheroidal galaxies
• Mass modelling of dwarf spheroidal galaxies: the effect of unbound stars from tidal tails and the Milky Way
• Dark matter distribution in the Draco dwarf from velocity moments
• Adventures of a tidally induced bar
• Stellar Kinematics of the Andromeda II Dwarf Spheroidal Galaxy
• The inner structure and kinematics of the Sagittarius dwarf galaxy as a product of tidal stirring
• The grouping, merging and survival of subhaloes in the simulated Local Group
• Prolate rotation and metallicity gradient in the transforming dwarf galaxy Phoenix
• Galaxies with prolate rotation in Illustris
• Formation of Dwarf Spheroidal Galaxies Via Mergers of Disky Dwarfs
• Andromeda II as a merger remnant
• The anatomy of Leo I: how tidal tails affect the kinematics
• Tidally induced bars in dwarf galaxies on different orbits around a Milky Way-like host
• Dynamical constraints on the dark matter distribution of the Sculptor dwarf spheroidal from stellar proper motions
• The Carina Project. X. On the kinematics of old and intermediate-age stellar populations
• The origin of prolate rotation in dwarf spheroidal galaxies formed by mergers of disky dwarfs
• Schwarzschild dynamical model of the Fornax dwarf spheroidal galaxy
• Rotating stellar populations in the Fornax dSph galaxy
• Recovering the mass profile and orbit anisotropy of mock dwarf galaxies with Schwarzschild modelling
• Tidally induced bars in gas-rich dwarf galaxies orbiting the Milky Way
• Dark halo structure in the Carina dwarf spheroidal galaxy: joint analysis of multiple stellar components
• The structure of Andromeda II dwarf spheroidal galaxy
• Formation of Andromeda II via a gas-rich major merger and an interaction with M31
• The effect of non-sphericity on mass and anisotropy measurements in dSph galaxies with Schwarzschild method