Dwarf Galaxy Dark Matter Density Profiles Inferred from Stellar and Gas Kinematics

Abstract

We present new constraints on the density profiles of dark matter (DM) halos in seven nearby dwarf galaxies from measurements of their integrated stellar light and gas kinematics. The gas kinematics of low mass galaxies frequently suggest that they contain constant density DM cores, while N-body simulations instead predict a cuspy profile. We present a data set of high resolution integral field spectroscopy on seven galaxies and measure the stellar and gas kinematics simultaneously. Using Jeans modeling on our full sample, we examine whether gas kinematics in general produce shallower density profiles than are derived from the stars. Although 2/7 galaxies show some localized differences in their rotation curves between the two tracers, estimates of the central logarithmic slope of the DM density profile, gamma, are generally robust. The mean and standard deviation of the logarithmic slope for the population are gamma=0.67+/-0.10 when measured in the stars and gamma=0.58+/-0.24 when measured in the gas. We also find that the halos are not under concentrated at the radii of half their maximum velocities. Finally, we search for correlations of the DM density profile with stellar velocity anisotropy and other baryonic properties. Two popular mechanisms to explain cored DM halos are an exotic DM component or feedback models that strongly couple the energy of supernovae into repeatedly driving out gas and dynamically heating the DM halos. We investigate correlations that may eventually be used to test models. We do not find a secondary parameter that strongly correlates with the central DM density slope, but we do find some weak correlations. Determining the importance of these correlations will require further model developments and larger observational samples. (Abridged)

29 pages, 18 figures, 10 tables, accepted for publication in ApJ

References in corpus (17)

• K-corrections and filter transformations in the ultraviolet, optical, and near infrared
• High-Resolution Rotation Curves and Galaxy Mass Models from THINGS
• The SAURON project -- X. The orbital anisotropy of elliptical and lenticular galaxies: revisiting the (V/sigma,epsilon) diagram with integral-field stellar kinematics
• Measuring the inclination and mass-to-light ratio of axisymmetric galaxies via anisotropic Jeans models of stellar kinematics
• Population Synthesis in the Blue IV: Accurate Model Predictions for Lick Indices and UBV Colors in Single Stellar Populations
• Triaxial orbit based galaxy models with an application to the (apparent) decoupled core galaxy NGC 4365
• High-resolution dark matter density profiles of THINGS dwarf galaxies: Correcting for non-circular motions
• A Revised Model for the Formation of Disk Galaxies: Low Spin and Dark-Halo Expansion
• GHASP : an H alpha kinematic survey of spiral and irregular galaxies. V. Dark matter distribution in 36 nearby spiral galaxies
• High Resolution Optical Velocity Fields of 11 Low Surface Brightness Galaxies
• The Impact of Feedback on Disk Galaxy Scaling Relations
• The chemical composition of red giant stars in four intermediate-age clusters of the Large Magellanic Cloud
• Measuring Ages and Elemental Abundances from Unresolved Stellar Populations: Fe, Mg, C, N, and Ca
• On the dark matter profile in Sculptor: Breaking the $\beta$ degeneracy with Virial shape parameters
• Bar-Halo Friction in Galaxies III: Halo Density Changes
• Ultra-Compact High Velocity Clouds as Minihalos and Dwarf Galaxies
• Non-Axisymmetric Structure in the Satellite Dwarf Galaxy NGC2976: Implications for its Dark/Bright Mass Distribution and Evolution

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