An astrophysical oscillator strength for the SII 94.7-nm resonance line and S abundances in DLAs

By using UV spectra for the O star HD 93521 taken with the ORFEUS II echell e spectrograph, we determine an 'astrophysical' f value for the S II lambda 94.7-nm line: f = 0.00498(-0.00138)(+0.00172,) error at 1 sigma- level. Th is is almost a factor of 30 smaller than the guessed value found in the Kur ucz data base (f = 0.1472), which was until now the only one available for this transition. We use our 'astrophysical' f to investigate the S abundanc e in two damped Ly alpha absorption systems (DLAs) observed with the UV-Vis ual Echelle Spectrograph (UVES) at the European Southern Observatory's 8.2- m Kueyen telescope. In the case of the absorber at Z(abs) = 3.02486 towards QSO 0347-3819, we find a sulphur column density which is consistent, withi n errors, with that determined by Centurion et al. by means of the lambda 1 25.9-nm line, thus providing an external check on the accuracy of our f val ue. For the damped absorber at Z(abs) = 4.4680 towards BR J0307-4945, we de termine a high value of the S abundance, which, however, is probably the re sult of blending with Ly alpha forest lines.