Atomic data for radioactive elements Ra I, Ra II, Ac I and Ac II and application to their detection in HD 101065 and HR 465^*

¹ Astrophysique et Spectroscopie, Université de Mons-Hainaut, 7000 Mons, Belgium e-mail: quinet@umh.ac.be
² IPNAS (Bât. B15), Université de Liège, Sart Tilman, 4000 Liège, Belgium
³ Astrophysical Research Center for the Structure and Evolution of the Cosmos, Sejong University, Seoul 143-747, South Korea
⁴ Astronomical Observatory, Odessa National University, Park Shevchenko, Odessa 65014, Ukraine

Received: 14 June 2007
Accepted: 13 August 2007

Abstract

Radiative data for transitions of astrophysical interest in radioactive elements Ra I, Ra II, Ac I and Ac II have been computed using a semi-empirical relativistic Hartree-Fock approach including core polarization effects. Most of the oscillator strengths reported in the present paper are new. A possible detection of radium (Ra II) and actinium (Ac II) in the spectrum of the stars HD 101065 and HR 465 is examined and discussed.