The Influence of Collisional Transfers and Perturbations on Measured A and B State Lifetimes in CN

Abstract

The influence of collisional transfers and perturbations on measured A and B state lifetimes in CN.

EINSTEIN A COEFFICIENTS AND OSCILLATOR STRENGTHS FOR THE A 2 Π- X 2 Σ + (RED) AND B 2 Σ + -X 2 Σ

“…In particular, the present values of 62. 74, 62.97, 63.46, 64.25, 65.39, 66.95 ns agree within ∼5% with the experimental values of Duric et al (1978), obtained with the high frequency deflection technique. The theoretical calculations of the oscillator strength of the B 2 Σ + -X 2 Σ + bands by and Bauschlicher & Langhoff (1988) predict f 0 0 = 0.0345 and 0.0335, respectively, compared to f 0 0 = 0.0337 in the present study.…”

“…However, the most recent experimental values of Taherian & Slanger (1984;6.67 ± 0.60 μs for v = 2 to 4.3 ± 0.85 μs for v = 5) and Lu et al (1992;6.96 ± 0.3 μs for v = 2 to 3.38 ± 0.2 μs for v = 5) show better agreement, at least for the lower vibrational levels. In contrast, the experimental lifetimes of the B 2 Σ + state obtained in different studies agree reasonably well with each other (Nishi et al 1982;Duric et al 1978;Jackson 1974;Luk & Bersohn 1973).…”

“…An earlier calculation by Larsson et al (1983) has provided a value of f 0 0 = 0.0324. Since the experimental lifetimes of the B 2 Σ + state (Nishi et al 1982;Duric et al 1978;Jackson 1974;Luk & Bersohn 1973) agree well with theoretical results (Cartwright & Hay 1982;Larsson et al 1983;Lavendy et al 1984;Bauschlicher & Langhoff 1988), an average value of f 0 0 = 0.033 was adopted by Bakker & Lambert (1998) in their study of the 12 CN and 13 CN lines of the red and violet systems in the spectrum of the post-asymptotic giant branch star HD 56126. Our value of f 0 0 = 0.0337 also supports the value adopted by Bakker & (A color version of this figure is available in the online journal.)…”

“…(1) Duric et al 1978; (2) relative increase of the lifetime per J level. In the X 2 Σ + state, the opposite is observed.…”

“…There have been many experimental studies of the lifetimes of the A 2 Π state (Jeunehomme 1965;Katayama et al 1979;Snedden & Lambert 1982;Nishi et al 1982;Duric et al 1978;Taherian & Slanger 1984;Lu et al 1992;Huang et al 1993;Halpern et al 1996) and the B 2 Σ + state (Nishi et al 1982;Duric et al 1978;Jackson 1974;Luk & Bersohn 1973) over the past four decades. It has been noted that the experimental lifetimes of the A 2 Π state reported by different groups show poor agreement with each other.…”