2015/09/23 by James Binney, T. Piffl, Tilmann Piffl · 63 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Dark matter #Dark matter halo #Galaxy #Galaxy rotation curve #Gamma-ray bursts and supernovae #Gravitational microlensing #Halo #Physics #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.1093/mnras/stv2225
published in Monthly Notices of the Royal Astronomical Society 454(4), 3653-3663 (Oxford University Press) · 11 pages MNRAS accepted
arxiv created 2015/09/23 · openalex publication_date 2015/10/20 · arxiv updated 2015/10/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Starting from the hypothesis that the Galaxy's dark halo responded adiabatically to the infall of baryons, we have constructed a self-consistent dynamical model of the Galaxy that satisfies a large number of observations, including measurements of gas terminal velocities and masers, the kinematics of 180 000 giant stars from the RAVE (RAdial Velocity Experiment) survey and star-count data from the Sloan Digital Sky Survey. The stellar disc and the dark halo are both specified by distribution functions of the action integrals. The model is obtained by extending the work of Piffl et al. from the construction of a single model to a systematic search of model space. Whereas the model of Piffl et al. violated constraints on the terminal-velocity curve, our model respects these constraints by adopting a long scalelength Rd = 3.66 kpc for the thin and thick discs. The model is, however, inconsistent with the measured optical depth for microlensing of bulge stars because it attributes too large a fraction of the density at R ≲ 3 kpc to dark matter rather than stars. Moreover, it now seems likely that the thick disc's scalelength is significantly shorter than the model implies. Shortening this scalelength would cause the constraints from the rotation curve to be violated anew. We conclude that we can now rule out adiabatic compression of our Galaxy's dark halo.