Probabilistic Inference of the Structure and Orbit of Milky Way Satellites with Semi-Analytic Modeling

Abstract

Semi-analytic modeling furnishes an efficient avenue for characterizing the properties of dark matter halos associated with satellites of Milky Way-like systems, as it easily accounts for uncertainties arising from halo-to-halo variance, the orbital disruption of satellites, baryonic feedback, and the stellar-to-halo mass (SMHM) relation. We use the SatGen semi-analytic satellite generator -- which incorporates both empirical models of the galaxy-halo connection in the field as well as analytic prescriptions for the orbital evolution of these satellites after they enter a host galaxy -- to create large samples of Milky Way-like systems and their satellites. By selecting satellites in the sample that match the observed properties of a particular dwarf galaxy, we can then infer arbitrary properties of the satellite galaxy within the Cold Dark Matter paradigm. For the Milky Way's classical dwarfs, we provide inferred values (with associated uncertainties) for the maximum circular velocity $v_{max}$ and the radius $r_{max}$ at which it occurs, varying over two choices of feedback model and two prescriptions for the SMHM relation that populate dark matter halos with physically distinct galaxies. While simple empirical scaling relations can recover the median inferred value for $v_{max}$ and $r_{max}$, this approach provides realistic correlated uncertainties and aids interpretability through variation of the model. For these different models, we also demonstrate how the internal properties of a satellite's dark matter profile correlate with its orbit, and we show that it is difficult to reproduce observations of the Fornax dwarf without strong baryonic feedback. The technique developed in this work is flexible in its application of observational data and can leverage arbitrary information about the satellite galaxies to make inferences about their dark matter halos and population statistics.

Published version. 15 pages, 7 figures; 9 pages of appendices with 6 supplementary figures. The code and data used in this work are available at https://github.com/folsomde/Semianalytic_Inference/

References in corpus (40)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Disruption of Dark Matter Substructure: Fact or Fiction?
• Generating Dark Matter Halo Merger Trees
• Dark Matter Substructure in Numerical Simulations: A Tale of Discreteness Noise, Runaway Instabilities, and Artificial Disruption
• Milky Way Satellite Census. II. Galaxy--Halo Connection Constraints Including the Impact of the Large Magellanic Cloud
• The Orbital Histories of Magellanic Satellites Using Gaia DR2 Proper Motions
• The Unorthodox Orbits of Substructure Halos
• Scaling Relations and the Fundamental Line of the Local Group Dwarf Galaxies
• Gaia early DR3 systemic motions of Local Group dwarf galaxies and orbital properties with a massive Large Magellanic Cloud
• The mass of our Milky Way
• Proper Motions, Orbits, and Tidal Influences of Milky Way Dwarf Spheroidal Galaxies
• The detailed structure and the onset of galaxy formation in low-mass gaseous dark matter haloes
• Limit on the LMC mass from a census of its satellites
• Diversity of dark matter density profiles in the Galactic dwarf spheroidal satellites
• Quantifying scatter in galaxy formation at the lowest masses
• SatGen: a semi-analytical satellite galaxy generator -- I. The model and its application to Local-Group satellite statistics
• The effect of the LMC on the Milky Way system
• The tidal evolution of dark matter substructure -- I. Subhalo density profiles
• The distinct stellar-to-halo mass relations of satellite and central galaxies: insights from the IllustrisTNG simulations
• Warm Dark Matter Constraints Using Milky-Way Satellite Observations and Subhalo Evolution Modeling
• The Dekel-Zhao profile: A mass-dependent dark-matter density profile with flexible inner slope and analytic potential, velocity dispersion, and lensing properties
• Nonlinear evolution of dark matter subhalos and applications to warm dark matter
• Symphony: Cosmological Zoom-in Simulation Suites over Four Decades of Host Halo Mass
• Structure Formation Models Weaken Limits on WIMP Dark Matter from Dwarf Spheroidal Galaxies
• Pre-processing, group accretion and the orbital trajectories of associated subhaloes
• The infall of dwarf satellite galaxies are influenced by their host's massive accretions
• LCDM halo substructure properties revealed with high resolution and large volume cosmological simulations
• Constraints on dark matter-neutrino scattering from the Milky-Way satellites and subhalo modeling for dark acoustic oscillations
• Cusp or core? Revisiting the globular cluster timing problem in Fornax
• SatGen -- II. Assessing the impact of a disc potential on subhalo populations
• Relating the Diverse Merger Histories and Satellite Populations of Nearby Galaxies
• Fornax globular cluster distributions: implications for the cusp-core problem
• Satellite mass functions and the faint end of the galaxy mass-halo mass relation in LCDM
• The Response of Dark Matter Haloes to Gas Ejection: CuspCore II
• Orbital distribution of infalling satellite halos across cosmic time
• Mass estimators for flattened dispersion-supported galaxies
• EDGE: Predictable Scatter in the Stellar Mass--Halo Mass Relation of Dwarf Galaxies
• Halo Densities and Pericenter Distances of the Bright Milky Way Satellites as a Test of Dark Matter Physics