Rotational velocities of A-type stars - I. Measurement of v sin i in the southern hemisphere

Within the scope of a Key Programme determining fundamental parameters of stars observed by HIPPARCOS, spectra of 525 B8 to F2-type stars brighter than V = 8 have been collected at ESO. Fourier transforms of several line profiles in the range 4200-4500 Angstrom are used to derive v sin i from the frequency of the first zero. Statistical analysis of the sample indicates that measurement error is a function of v sin i and this relative error of the rotational velocity is found to be about 6% on average. The results obtained are compared with data from the literature. There is a systematic shift from standard values from Slettebak et al. (1975), which are 10 to 12% lower than our findings. Comparisons with other independent v sin i values tend to prove that those from Slettebak et al. are underestimated. This effect is attributed to the presence of binaries in the standard sample of Slettebak et al., and to the model atmosphere they used.