The Dark Matter Density in the Solar Neighborhood reconsidered

Abstract

Both the gas flaring and the dip in the rotation curve, which was recently reconfirmed with precise measurements using the VERA VLBI array in Japan, suggest doughnut-like substructure in the dark matter (DM) halo. A global fit to all available data shows that the data are indeed best described by an NFW DM profile complemented by two doughnut-like DM substructures with radii of 4.2 and 12.4 kpc, which coincide with the local dust ring and the Monocerus ring of stars, respectively. Both regions have been suggested as regions with tidal streams from "shredded" satellites. If real, the radial extensions of these nearby ringlike structures enhance the local dark matter density by a factor of four to about 1.3$\pm 0.3$ GeV/cm${}^3$. It is shown that i) this higher DM density is perfectly consistent with the local gravitational potential determining the surface density and the local matter density (Oort limit), ii) previous determinations of the surface density were biased by the assumption of a smoothly varying DM halo and iii) the s-shaped gas flaring is explained. Such a possible enhancement of the local DM density is of great interest for direct DM searches and would change the directional dependence for indirect DM searches.

14 pages, 4 figures, extended version, accepted for publication in JCAP

References in corpus (6)

• Outer structure of the Galactic warp and flare: explaining the Canis Major over-density
• Dark matter in the Milky Way, II. the HI gas distribution as a tracer of the gravitational potential
• Assembly History and Structure of Galactic Cold Dark Matter Halos
• Cold Dark Matter Substructure and Galactic Disks II: Dynamical Effects of Hierarchical Satellite Accretion
• Spiral structure of the Third Galactic Quadrant and the solution to the Canis Major debate
• Origins of the Thick Disk as Traced by the Alpha-Elements of Metal-Poor Giant Stars Selected from RAVE

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• Impact of a Pioneer/Rindler-type acceleration on the Oort cloud
• Dark Matter Decay and the Abundance of Ultracompact Minihalos
• Estimating the Spin-Independent WIMP-Nucleon Coupling from Direct Dark Matter Detection Data
• Constraining the Milky Way Dark Matter Density Profile with Gamma-Rays with Fermi-LAT
• Phenomenology of wavelike vector dark matter nonminimally coupled to gravity
• Constraining dark matter sub-structure with the dynamics of astrophysical systems
• Effects of Residue Background Events in Direct Dark Matter Detection Experiments on the Estimation of the Spin-Independent WIMP-Nucleon Coupling
• Dark matter signals at the LHC: forecasts from ton-scale direct detection experiments
• Testing universal dark-matter caustic rings with galactic rotation curves