Li I spectra in the 4.65–8.33 micron range: high-L states and oscillator strengths

0380233 - ÚFCH JH 2013 RIV FR eng J - Článek v odborném periodiku
Civiš, Svatopluk - Ferus, Martin - Kubelík, Petr - Chernov, Vladislav E. - Zanozina, Ekaterina M.
Li I spectra in the 4.65–8.33 micron range: high-L states and oscillator strengths.
Astronomy & Astrophysics. Roč. 545, September (2012), A61. ISSN 0004-6361. E-ISSN 1432-0746
Grant CEP: GA AV ČR IAAX00100903
Grant ostatní: GA MF(CZ) ECPF:049/4V
Institucionální podpora: RVO:61388955
Klíčová slova: atomic data * identification - methods * spectroscopy
Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
Impakt faktor: 5.084, rok: 2012

Context. Infrared (IR) astronomy capacities have rapidly developed in recent years thanks to several ground- and space-based facilities. To take advantage of these capabilities efficiently, a large amount of atomic data (such as line wavenumber, excited-level energy values, and oscillator strengths) are needed. These data are incomplete, in particular, for lithium whose abundances are important for several astrophysical problems. Aims. No laboratory-measured spectra of Li I have been reported for wavelengths longward of 6.6 microns. We aim to find new Li I lines in the 4.65–8.33 microns range due to transitions between states with high orbital momentum (l ≥ 4) and to determine the excitation energies of these states. Methods. The Li I lines were studied using the time-resolved Fourier transform infrared spectroscopy of a plasma created by the laser ablation of a LiF target in a vacuum. The classification of the lines was performed by accounting for oscillator strengths (f-values) calculated using quantum defect theory (QDT). The adequacy of QDT for these calculations was checked by comparison with the available experimental and theoretical results. Results. We report four new Li I lines in the 900–2200 cm-1 range that allow us to extract the excitation energies of the 6g, 6h, and 7h states of Li I, which have not been measured before. We also provide a large list of QDT-calculated f-values for Li I in the range of 1–20 microns.
Trvalý link: http://hdl.handle.net/11104/0218480