NGC 6167 253 , the SIMBAD biblio

We report here the results of a detailed study of two surveys of H I, at λ= 21 cm, in the field of the stellar association Ara OB1. Subtracting the background with a procedure developed here, we were able to identify two H I shell-like features, at roughly the same position but at different velocities, whose parameters were determined. On the basis of their kinematical distances, two concentrations of OB stars (one at 1400 pc, belonging to Ara OB1, and another at 2500 pc) might be the progenitors of these shells. The nearest H I shell may have triggered a process of star formation.