Lifetimes of 5d96pand 5d86s6plevels in Hg iii

Experimental and theoretical studies of lifetimes and transition probabilities for doubly ionized mercury, Hg i i i, are reported. Such data are currently of great astrophysical interest because observations with the Goddard high resolution spectrograph on board the Hubble space telescope have shown some 5${\mathit{d}}^9$6s-5${\mathit{d}}^9$6p transitions of Hg i i i in the spectrum of the chemically peculiar star χ Lupi. We now report experimental lifetimes for some selected 5${\mathit{d}}^9$6p and 5${\mathit{d}}^8$6s6p levels, determined by beam-foil spectroscopy, and compare the results with theoretical transition probabilities based on relativistic multiconfiguration Dirac-Fock calculations.