## Abstract

Line strengths have been calculated in the form of Einstein A coefficients and f-values for a large number of bands of the A ^{2}Π-X ^{2}Σ^{+} and B ^{2}Σ^{+}-X ^{2}Σ^{+} systems and rovibrational transitions within the X ^{2}Σ^{+} state of CN using Western's PGOPHER program. The J dependence of the transition dipole moment matrix elements (the Herman-Wallis effect) has been taken into account. Rydberg-Klein-Rees potential energy functions for the A ^{2}Π, B ^{2}Σ^{+} , and X ^{2}Σ^{+} states were computed using spectroscopic constants from the A ^{2}Π-X ^{2}Σ^{+} and B ^{2}Σ^{+}-X ^{2}Σ^{+} transitions. New electronic transition dipole moment functions for these systems and a dipole moment function for the X ^{2}Σ^{+} state were generated from high level ab initio calculations and have been used in Le Roy's LEVEL program to produce transition dipole moment matrix elements (including their J dependence) for a large number of vibrational bands. The program PGOPHER was used to calculate Einstein A coefficients, and a line list was generated containing the observed and calculated wavenumbers, Einstein A coefficients and f-values for 290 bands of the A ^{2}Π-X ^{2}Σ ^{+} transition with v′ = 0-22, v″ = 0-15, 250 bands of the B ^{2}Σ^{+}-X ^{2}Σ^{+} transition with v′ = 0-15, v″ = 0-15 and 120 bands of the rovibrational transitions within the X ^{2}Σ^{+} state with v = 0-15. The Einstein A coefficients have been used to compute radiative lifetimes of several vibrational levels of the A ^{2}Π and B ^{2}Σ ^{+} states and the values compared with those available from previous experimental and theoretical studies.

Original language | English |
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Article number | 23 |

Number of pages | 15 |

Journal | Astrophysical Journal Supplement Series |

Volume | 210 |

Issue number | 2 |

DOIs | |

Publication status | Published - 1 Feb 2014 |

## Keywords

- astronomical databases: miscellaneous
- methods: laboratory: molecular
- molecular data
- opacity
- stars: abundances
- techniques: spectroscopic