Revealing Gas Inflows Toward the Galactic Central Molecular Zone

We study the gas inflows toward the Galactic Central Molecular Zone (CMZ) based on the gas morphological and kinematic features from the Milky Way Imaging Scroll Painting in the region of l = 1.degrees 2-19.degrees 0 and divided by b divided by less than or similar to 3.degrees 0. We find that the near dust lane appears to extend to l similar to 15 degrees, in which the end of the large-scale gas structure intersects with the 3 kpc ring at a distance of similar to 5 kpc. Intriguingly, many filamentary molecular clouds (MCs), together with the bow-like/ballistic-like clouds and continuous CO features with notable velocity gradient, are finely outlined along the long structure. These MCs also have relatively large velocity dispersions, indicating the shocked gas generated by local continuous accretion and thus the enhanced turbulence along the entire gas structure. We suggest that the similar to 3.1-3.6 kpc-long CO structure originates from the accretion molecular gas driven by the Galactic bar. The gas near the bar end at the 3 kpc ring region becomes an important reservoir for the large-scale accreting flows inward to the CMZ through the bar channel. The inclination angle of the bar is estimated to be phi bar = 23 degrees +/- 3 degrees, while the pattern speed of the bar is Omega bar less than or similar to 32.5 +/- 2.5 km s-1 kpc-1. The total mass of the whole near gas lane is about 1.3 +/- 0.4 x 107 M circle dot according to the calculated X CO similar to 1.0 +/- 0.4 x 1020 cm-2(K km s-1)-1 from the large-scale 12CO and 13CO data and the complementary H i data. We revisit the gas inflow rate as a mean value of 1.1 +/- 0.3 M circle dot yr-1, which seems to be comparable to the outflow's rate of the Galactic nuclear winds after applying the updated lower X-factor above.