2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/13516We report simulations of the gas flow in the gravitational potential of the COBE NIR bulge and disk. These models lead to four--armed spiral structure between corotation of the bar and the Sun, in agreement with the observed spiral arm tangents. The 3-kpc-arm is identified with one of the arms emanating from the ends of the bar.Latex, 4 pages, 2 figures. To appear in the proceedings of the `Galaxy Dynamics' conference held at Rutgers Univ., August 8-12, 1998Astrophysicstext