Dynamical model of the Milky Way using APOGEE and Gaia data
  We construct a dynamical model of the Milky Way disk from a data set, which
combines Gaia EDR3 and APOGEE data throughout Galactocentric radii between
$5.0\leq R\leq19.5$ kpc. We make use of the spherically-aligned Jeans
Anisotropic Method to model the stellar velocities and their velocity
dispersions. Building upon our previous work, our model now is fitted to
kinematic maps that have been extended to larger Galactocentric radii due to
the expansion of our data set, probing the outer regions of the Galactic disk.
Our best-fitting dynamical model suggests a logarithmic density slope of
$\alpha_{\rm DM}=-1.602\pm0.079_{\rm syst}$ for the dark matter halo and a dark
matter density of $\rho_{\rm DM}(R_{\odot})=(8.92\pm0.56_{\rm syst})\times
10^{-3}$ M$_{\odot}$ pc$^{-3}$ ($0.339\pm0.022_{\rm syst}$ GeV cm$^{3}$). We
estimate a circular velocity at the solar radius of $v_{\rm
circ}=(234.7\pm1.7_{\rm syst})$ km s$^{-1}$ with a decline towards larger
radii. The total mass density is $\rho_{\rm
tot}(R_{\odot})$=$(0.0672\pm0.0015_{\rm syst})$ M$_{\odot}$ pc$^{-3}$ with a
slope of $\alpha_{\rm tot}$=$-2.367\pm0.047_{\rm syst}$ for $5\leq R\leq19.5$
kpc and the total surface density is $\Sigma(R{_\odot}, |z|\leq$ 1.1
kpc)=$(55.5\pm1.7_{\rm syst})$ M$_{\odot}$ pc$^{-2}$. While the statistical
errors are small, the error budget of the derived quantities is dominated by
the 3 to 7 times larger systematic uncertainties. These values are consistent
with our previous determination, but systematic uncertainties are reduced due
to the extended data set covering a larger spatial extent of the Milky Way
disk. Furthermore, we test the influence of non-axisymmetric features on our
resulting model and analyze how a flaring disk model would change our findings.
