Weighing the Galactic disk using phase-space spirals II. Most stringent constraints to a thin dark disk using Gaia EDR3

Understand

Using the method that was developed in the first paper of this series, we measure the vertical gravitational potential of the Galactic disk from the time-varying structure of the phase-space spiral, using data from Gaia as well as supplementary radial velocity information from legacy spectroscopic surveys.

• For eleven independent data samples, we inferred gravitational potentials that were in good agreement, despite the data samples' varied and substantial selection effects.
• Using a model for the baryonic matter densities, we inferred a local halo dark matter density of $0.0085 \pm 0.0039$ M$_\odot$/pc$^3 = 0.32 \pm 0.15$ GeV/cm$^3$.
• We were also able to place the most stringent constraint to the surface density of a thin dark disk with a scale height $\leq 50$ pc: an upper 95 % confidence limit of roughly 5 M$_\odot$/pc$^2$ (compared to previous limit of roughly 10 M$_\odot$/pc$^2$, given the same scale height).