Radiative lifetime measurements and oscillator strengths of astrophysical interest in Ho III

¹ Department of Physics, Lund Institute of Technology, PO Box 118, 22100 Lund, Sweden
² Astrophysique et Spectroscopie, Université de Mons-Hainaut, 7000 Mons, Belgium
³ IPNAS, Bât. B15, Université de Liège, Sart Tilman, 4000 Liège, Belgium

Corresponding author: E. Biémont, E.Biemont@ulg.ac.be

Received: 26 July 2001
Accepted: 14 December 2001

Abstract

Radiative lifetimes of three long-lived levels belonging to the 4f¹⁰5d configuration of Ho III have been measured, for the first time, using the time-resolved laser-induced fluorescence technique. A good agreement between the experimental lifetimes and theoretical results obtained within a multiconfigurational pseudo-relativistic Hartree-Fock (HFR) approach including core-polarization (CP) effects is observed provided an adequate scaling factor is applied to the <4fr5d> transition matrix element. From the comparison theory–experiment, it has been possible to assess the reliability of the oscillator strengths of the 4f–5d transitions of astrophysical interest, particularly for the lines depopulating the levels considered in the present work. The present results fill in a gap concerning the f-values of doubly ionized holmium and are needed for a quantitative evaluation of the holmium abundance in some peculiar stars.