6.9. Interpreting the main HI and CO ℓ–V features in the Galactic bar from self-consistent stellar and gas dynamical models

Extract

We propose a new picture accounting for the dominant features in the observed ℓ−V distribution of the Milky Way gas within the central few kpcs, based on the gas flow in two self-consistent and symmetry-free barred dynamical models. These models are snapshots selected from high resolution 3D N-body and SPH simulations with 4 × 10⁶ stellar and dark particles and 1.5 × 10⁵ gas particles, and with initial conditions adapted from Fux (1997). The main results are shown in figure 1. In both models, the inclination angle of the bar relative to the Sun-Galactic centre line is 25°, the corotation radius close to 4.4 kpc and the sound speed of the gas 10 km s⁻¹.