OUR GALACTIC-CENTER - A LABORATORY FOR THE FEEDING OF ACTIVE GALACTICNUCLEI

We demonstrate that our Galactic Center, despite little evidence for t he presence of a currently active nucleus, provides insight into the f eeding of AGN: The observed velocity field of molecular clouds can be interpreted as tracing out the spiralling inwards of gas in a large ac cretion flow towards the Galactic Center (Linden et al. 1993; Biermann et al. 1993) in the radial distance range from a few parsec to a few hundred pc. The required effective viscosity corresponds well to the o bserved turbulent velocities and characteristic length scales. The imp lied mass influx provides indeed all the material needed to maintain t he presently observed star formation rate at distances closer than abo ut 100 pc. We argue that the energy input from supernova explosions du e to the high rate of star formation can feed the turbulence of the in terstellar medium. This then keeps the effective viscosity high as req uired to feed the star formation. We suggest that this process leads t o limit cycles in star formation, and as a consequence also to limit c ycles in the feeding of any activity at the very center.