Massive O- and B-type stars velocities

It has been proposed to be a spectroscopic signature of the presence of stellar oscillations; however, we still lack a definitive confirmation of this hypothesis. We aim to provide new empirical clues about macroturbulent spectral line broadening in O- and B-type stars to evaluate its physical origin.

We used high-resolution spectra of 430 stars with spectral types in the range O4-B9 (all luminosity classes) compiled in the framework of the IACOB project. We characterized the line broadening of adequate diagnostic metal lines using a combined Fourier transform and goodness-of-fit technique. We performed a quantitative spectroscopic analysis of the whole sample using automatic tools coupled with a huge grid of FASTWIND models to determine their effective temperatures and gravities.