Line List for the A2Π−X2Σ+ and the B2Σ+−X2Σ+ Band Systems of CaF
The spectral analysis of molecule-rich asymptotic giant branch (AGB) stars is challenging. Although other calcium and fluorine bearing molecules are observed in the microwave and in the visible spectrum of AGB stars, CaF has never been detected, despite favorable chemical equilibrium predictions. Ye...
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IOP Publishing
2025-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad9c7a |
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| author | Léo Lavy Peter F Bernath Adam Pastorek |
| author_facet | Léo Lavy Peter F Bernath Adam Pastorek |
| author_sort | Léo Lavy |
| collection | DOAJ |
| description | The spectral analysis of molecule-rich asymptotic giant branch (AGB) stars is challenging. Although other calcium and fluorine bearing molecules are observed in the microwave and in the visible spectrum of AGB stars, CaF has never been detected, despite favorable chemical equilibrium predictions. Yet, measuring the CaF abundance could give more insight into the fluorine budget of AGB stars and allow better simulation of stellar spectra. In this work, we present an analysis of the visible spectrum of CaF obtained with a Fourier transform spectrometer. CaF A ^2 Π− X ^2 Σ ^+ and B ^2 Σ ^+ − X ^2 Σ ^+ band systems were excited with a hollow cathode discharge. Using previous fluorescence spectroscopy measurements, highly accurate ground state constants, and reasonable extrapolation schemes, the strongest features of CaF in the visible spectrum can be accurately modeled for both band systems. Spectroscopic constants are determined for A ^2 Π with v ≤ 16 and for B ^2 Σ ^+ with v ≤ 20. Ab initio transition dipole moment curves of both transitions were calculated and scaled, and we provide a line list with Einstein A coefficients and oscillator strengths. This line list can be used to simulate spectra of CaF at temperatures and pressures relevant to astrophysical environments. |
| format | Article |
| id | doaj-art-796b54f799fe4c019cc6d2106d8da449 |
| institution | Kabale University |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
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| series | The Astrophysical Journal |
| spelling | doaj-art-796b54f799fe4c019cc6d2106d8da4492025-01-15T14:32:39ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-0197911910.3847/1538-4357/ad9c7aLine List for the A2Π−X2Σ+ and the B2Σ+−X2Σ+ Band Systems of CaFLéo Lavy0https://orcid.org/0000-0003-4572-8612Peter F Bernath1https://orcid.org/0000-0002-1255-396XAdam Pastorek2https://orcid.org/0000-0001-7935-8571Department of Chemistry and Biochemistry, Old Dominion University , Norfolk, VA 23529, USADepartment of Chemistry and Biochemistry, Old Dominion University , Norfolk, VA 23529, USA; Department of Physics, Old Dominion University , Norfolk, VA 23529, USADepartment of Chemistry and Biochemistry, Old Dominion University , Norfolk, VA 23529, USAThe spectral analysis of molecule-rich asymptotic giant branch (AGB) stars is challenging. Although other calcium and fluorine bearing molecules are observed in the microwave and in the visible spectrum of AGB stars, CaF has never been detected, despite favorable chemical equilibrium predictions. Yet, measuring the CaF abundance could give more insight into the fluorine budget of AGB stars and allow better simulation of stellar spectra. In this work, we present an analysis of the visible spectrum of CaF obtained with a Fourier transform spectrometer. CaF A ^2 Π− X ^2 Σ ^+ and B ^2 Σ ^+ − X ^2 Σ ^+ band systems were excited with a hollow cathode discharge. Using previous fluorescence spectroscopy measurements, highly accurate ground state constants, and reasonable extrapolation schemes, the strongest features of CaF in the visible spectrum can be accurately modeled for both band systems. Spectroscopic constants are determined for A ^2 Π with v ≤ 16 and for B ^2 Σ ^+ with v ≤ 20. Ab initio transition dipole moment curves of both transitions were calculated and scaled, and we provide a line list with Einstein A coefficients and oscillator strengths. This line list can be used to simulate spectra of CaF at temperatures and pressures relevant to astrophysical environments.https://doi.org/10.3847/1538-4357/ad9c7aSpectral line listsLaboratory astrophysicsMolecular spectroscopyMolecular spectroscopic constants |
| spellingShingle | Léo Lavy Peter F Bernath Adam Pastorek Line List for the A2Π−X2Σ+ and the B2Σ+−X2Σ+ Band Systems of CaF The Astrophysical Journal Spectral line lists Laboratory astrophysics Molecular spectroscopy Molecular spectroscopic constants |
| title | Line List for the A2Π−X2Σ+ and the B2Σ+−X2Σ+ Band Systems of CaF |
| title_full | Line List for the A2Π−X2Σ+ and the B2Σ+−X2Σ+ Band Systems of CaF |
| title_fullStr | Line List for the A2Π−X2Σ+ and the B2Σ+−X2Σ+ Band Systems of CaF |
| title_full_unstemmed | Line List for the A2Π−X2Σ+ and the B2Σ+−X2Σ+ Band Systems of CaF |
| title_short | Line List for the A2Π−X2Σ+ and the B2Σ+−X2Σ+ Band Systems of CaF |
| title_sort | line list for the a2π x2σ and the b2σ x2σ band systems of caf |
| topic | Spectral line lists Laboratory astrophysics Molecular spectroscopy Molecular spectroscopic constants |
| url | https://doi.org/10.3847/1538-4357/ad9c7a |
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