A DIRECT IMAGE OF WIND INTERACTION IN THE POST-AGB EVOLUTION - CO OBSERVATIONS OF M1-92

We present high-resolution CO J = 1-0 maps of the protoplanetary nebula M1-92, Minkowski's Footprint, obtained with the IRAM interferometer at Plateau de Bure. The cartography is particularly revealing. Three components are distinguished in the maps: a bipolar outflow, with a (deprojected) velocity of similar to 65 km s(-1), a hollow prolate structure, with an axial velocity increasing with the distance to the star up to similar to 60 km s(-1) and a central condensation with velocities smaller than 10 km s(-1). A remarkable continuity in position and velocity is found between the hollow component and the bipolar flow. We argue that these properties indicate that an important dynamical interaction between both features is active at the present moment and affects most of the nebular material. Such an interaction would consist in a significant momentum transport from the bipolar fast flow to the rest of the nebula.