1999A&A...345..499B

In this paper we present theoretical simulations concerning the luminosity function of cluster WDs, computed under various assumptions about cluster age and IMF. Quantitative evaluations are discussed, showing that the WD cooling sequence can be divided into a portion at large luminosity where the distribution depends on cooling times only, and a narrow interval of luminosities at the bottom of the sequence that gives information about both cluster age and IMF. Detailed theoretical predictions are reported for a range of cluster ages covering the current estimates for the ages of globular and old galactic clusters, discussing theoretical expectations concerning the number ratio of WD to HB stars as a function of both cluster age and IMF. Finally, we discuss old galactic clusters as relevant targets for future observations.