Metal abundances in the hot DA white dwarfs Wolf 1346 and Feige 24.

Abstract

Photospheric metal lines observed in high-dispersion IUE spectra of the hot DA white dwarfs Wolf 1346 and Feige 24 are analyzed with detailed model synthetic spectra in order to derive metal abundances in the two stars. The IUE images used in the analysis are first discussed together with the theoretical framework, an extensive set of metal line profiles and equivalent widths calculated by Henry, Shipman, and Wesemael (1985). The results of the abundance analysis was summarized, and the determination of the projected rotational velocity of Feige 24 based on the synthetic profile calculations is considered. The new abundance determinations are discussed within the context of the occurrence of diffusion and accretion processes in white dwarf photospheres, and their importance is emphasized.