Beryllium abundances in metal-poor stars

Abstract

We have determined beryllium (Be) abundances for 25 metal-poor stars based on the high-resolution and high signal-to-noise ratio spectra from the Very Large Telescope/Ultraviolet and Visual Echelle Spectrograph data base. Our results confirm that Be abundances increase with Fe, supporting the global enrichment of Be in the Galaxy. Oxygen abundances based on the [O i] forbidden line imply a linear relation with a slope close to one for the Be versus O trend, which indicates that Be is probably produced in a primary process. Some strong evidence is found for the intrinsic dispersion of Be abundances at a given metallicity. The deviation of HD 132475 and HD 126681 from the general Be versus Fe and Be versus O trends favours the predictions of the superbubble model. However, the possibility that such dispersion originates from the inhomogeneous enrichment in Fe and O of the protogalactic gas cannot be excluded. © 2008 RAS.