We use Schwarzschild's orbit-superposition technique to construct self-consistent models of the Galactic bar. Using $\chi^2$ minimisation, we find that the best-fit Galactic bar model has a pattern speed $\Omega_{ \rm p}=60 \rm{ km s^{ -1} kpc^{ -1}}$, disk mass $\rm{ M_{ \rm d}=1.0\times10^{ 11}M_{ \odot}}$ and bar angle $\theta_{ \rm bar}=20^{ \circ}$ for an adopted bar mass $\rm{ M_{ \rm bar}=2\times10^{ 10}M_{ \odot}}$. The model can reproduce not only the three-dimensional and projected density distributions but also velocity and velocity dispersion data from the BRAVA survey. We also predict the proper motions in the range $l=[-12^{ \circ},12^{ \circ}]$, $b=[-10^{ \circ},10^{ \circ}]$, which appear to be higher than observations in the longitudinal direction. The model is stable within a timescale of 0.5 Gyr, but appears to deviate from steady-state on longer timescales. Our model can be further tested by future observations such as those from GAIA.
Categories: astro-ph.GA