Determining the Local Dark Matter Density with SDSS G-dwarf data

We present a determination of the local dark matter density derived using the integrated Jeans equation method presented in Silverwood et al. (2016) applied to SDSS-SEGUE G-dwarf data processed by Budenbender et al. (2015). For our analysis we construct models for the tracer density, dark matter and baryon distribution, and tilt term (linking radial and vertical motions), and then calculate the vertical velocity dispersion using the integrated Jeans equation. These models are then fit to the data using MultiNest, and a posterior distribution for the local dark matter density is derived. We find the most reliable determination to come from the α-young population presented in Budenbender et al. (2015), yielding a result of ρDM = 0.46+0.07 −0.09 GeV cm−3 = 0.012+0.001 −0.002 M⊙ pc−3. Our results also illuminate the path ahead for future analyses using Gaia DR2 data, highlighting which quantities will need to be determined and which assumptions could be relaxed.