TOWARD A MORE CONSISTENT EVOLUTION MODEL FOR THE LOCAL GALACTIC DISK

Infall models for the evolution of the local galactic disk were studie d and confronted with a large number of observational constraints from the solar vicinity, inclusive of the white dwarf luminosity function. The models are characterized as follows: 1. The key-functions (SFR, I MF, gas infall rate) are not prescribed by simple laws, but are direct ly derived from observational constraints. 2. A scatter in the metalli city at fixed age is considered which partly reflects inhomogeous chem ical evolution. 3. Special attention is drawn to the internal consiste ncy of the models. 4. In addition to infall of low-metallicity gas, me tal-enriched outflows are allowed. The ''best'' model is characterized by a disk age of almost-equal-to 12 Gyr, a SFR which is decreasing ov er the first half and is nearly constant over the second half of the d isk evolution, and by a similar temporal run of the gas infall rate. M oderate metal-enriched outflow can not be excluded.