The Caustic Ring Model of the Milky Way Halo

Abstract

We present a proposal for the full phase space distribution of the Milky Way halo. The model is axially and reflection symmetric and its time evolution is self-similar. It describes the halo as a set of discrete dark matter flows with stated densities and velocity vectors everywhere. We first discuss the general conditions under which the time evolution of a cold collisionless self-gravitating fluid is self-similar, and show that symmetry is not necessary for self-similarity. When spherical symmetry is imposed, the model is the same as described by Fillmore and Goldreich, and by Bertschinger, twenty-three years ago. The spherically symmetric model depends on one dimensionless parameter $\epsilon$ and two dimensionful parameters. We set $\epsilon$ = 0.3, a value consistent with the slope of the power spectrum of density perturbations on galactic scales. The dimensionful parameters are determined by the Galactic rotation velocity (220 km/s) at the position of the Sun and by the age of the Galaxy (13.7 Gyr). The properties of the outer caustics are derived in the spherically symmetric model. The structure of the inner halo depends on the angular momentum distribution of the dark matter particles. We assume that distribution to be axial and reflection symmetric, and dominated by net overall rotation. The inner caustics are rings whose radii are determined in terms of a single additional parameter $j_{\max }$. We summarize the observational evidence in support of the model. The evidence is consistent with $j_{\max }$ = 0.18 in Concordance Cosmology, equivalent to $j_{\max ,\mathrm{old}}$ = 0.26 in Einstein - de Sitter cosmology. We give formulas to estimate the flow densities and velocity vectors anywhere in the Milky Way halo. The properties of the first forty flows at the location of the Earth are listed.

arXiv comment35 pages, 6 figures

References in corpus (49)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• The Structure of Cold Dark Matter Halos
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Preliminary Maps and Basic Results
• Resolving the Structure of Cold Dark Matter Halos
• The Ghost of Sagittarius and Lumps in the Halo of the Milky Way
• First Results from the XENON10 Dark Matter Experiment at the Gran Sasso National Laboratory
• A Low Latitude Halo Stream around the Milky Way
• One Ring to Encompass them All: A giant stellar structure that surrounds the Galaxy
• Limits on WIMP dark matter using scintillating CaWO4 cryogenic detectors with active background suppression
• Dark Matter particles in the galactic halo: results and implications from DAMA/NaI
• The published extended rotation curves of spiral galaxies: Confrontation with Modified Dynamics
• More Satellites of Spiral Galaxies
• Improved Exclusion Limits from the EDELWEISS WIMP Search
• A High Resolution Search for Dark-Matter Axions
• Weak Lensing with SDSS Commissioning Data: The Galaxy-Mass Correlation Function To 1/h Mpc
• Two measures of the shape of the Milky Way's dark halo
• The secondary infall model of galactic halo formation and the spectrum of cold dark matter particles on Earth
• First limits on WIMP nuclear recoil signals in ZEPLIN-II: a two phase xenon detector for dark matter detection
• WIMP Annual Modulation with Opposite Phase in Late-Infall Halo Models
• The fine-grained phase-space structure of Cold Dark Matter halos
• Two body relaxation in CDM simulations
• Caustic rings of dark matter
• The velocity peaks in the cold dark matter spectrum on Earth
• Diurnal and Annual Modulation of Cold Dark Matter Signals
• The caustic ring singularity
• Evidence for Ring Caustics in the Milky Way
• Results of a Search for Cold Flows of Dark Matter Axions
• Demonstrating Discreteness and Collision Error in Cosmological N-body Simulations of Dark Matter Gravitational Clustering
• Neutralino Gamma-ray Signals from Accreting Halo Dark Matter
• The Inner Caustics of Cold Dark Matter Halos
• Searching for Supersymmetric Dark Matter - The Directional Rate and the Modulation Effect Due to Caustic Rings
• A potential WIMP signature for the caustic ring halo model
• Fine Structure of Dark Matter Halos and its Effect on Terrestrial Detection Experiments
• Particle Annihilation in Cold Dark Matter Micropancakes
• Robustness of Discrete Flows and Caustics in Cold Dark Matter Cosmology
• Evidence for universal structure in galactic halos
• Power-law correlation and discreteness in cosmological N-body simulations
• Does the Second Caustic Ring of Dark Matter Cause the Monoceros Ring of Stars ?
• Dark matter caustics and the enhancement of self-annihilation flux
• Gravitational Lensing by Cold Dark Matter Catastrophes
• A further look at particle annihilation in dark matter caustics
• Gravitational Lensing by Dark Matter Caustics
• Two Body Relaxation in Simulated Cosmological Haloes
• Probing dark matter caustics with weak lensing
• $\gamma$-ray flux from Dark Matter Annihilation in Galactic Caustics
• WIMP annihilation in caustics
• Gravitational Lensing and Structural Stability of Dark Matter Caustic Rings
• Probing Cold Dark Matter Cusps by Gravitational Lensing

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