Core mass of 3 – 9 M@ stars determined Uung binding energy criteria

Cataclysmic variables (CVs) are systems in which a white dwarf (WD) is accreting mass from a low-mass late-type Roche-lobe filling secondary star. In our recent numerical population synthesis of CVs at the post-common-envelope phase we found a white dwarf mass distribution that is consistent with that obtained observationally from Sloan Digital Sky Survey (SDSS). An interesting feature is a small peak around 0.9 M@. Previously we have investigated further systems producing white dwarfs mass of that size, and found that during their evolution, stars with initial mass around ~3 – 9 M@ will have an episode of decreasing core mass, when hydrogen exhausted layer is used to estimate the core mass. In this paper we discuss the results of using other criteria, related to the envelope binding energy, for core mass estimation and a possible link to the initial-final mass relation of WDs.