Accurate Calculation of Mgii3s–npOscillator Strengths

C. E. Theodosiou, S. R. Federman
1999 Astrophysical Journal  
A careful and accurate semiempirical calculation of transition matrix elements yielded the oscillator strengths of resonance lines for the lowest np conÐgurations in Mg II. Through an extension of previous work, particular attention was given to the determination of branching ratios for the Ðne-structure levels in the upper states. The new f-values provide strong theoretical support to the recent astronomical determinations by Fitzpatrick (1997) and could settle the question of the Mg abundance
more » ... in the interstellar medium. The branching ratio a value that deviates from the assumed ratio f (3sÈ4p 3@2 )/f (3sÈ4p 1@2 ) \ 1.78, of 2 used in earlier work.
doi:10.1086/308088 fatcat:wnvmfecbhbbpnmqfztnhs3zbuu