Abstract

We report the discovery of an outow and a molecular cavity at the Norma near-arm around the young Super Star Cluster (SSC) Westerlund 1 (Wd1). Association of the SSC Wd1 with the cavity and the molecular out-ow is discussed based on the observed kinematics from CO and HI emission, and also in the observed HI absorptions. We conclude that the possibility of association of Wd1 with the cavity is high if both are located at a distance of 5.0±0.5Kpc, which is a factor 1.4 farther than the most recent distance estimation to Wd1. The shell surrounding the cavity has a molecular mass of 1 × 10 6 M ? and is expanding at a velocity of 8 km s -1. The corresponding kinetic energy of expansion is 1 × 10 51 erg. The magnetar associated with Wd1 could be the source of this energy. © 2010: Instituto de Astronomía, UNAM.