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

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. © ESO 2007.