The Spectrum of Thorium from 250 nm to 5500 nm: Ritz Wavelengths and Optimized Energy Levels
| Autor: | Stephen L. Redman, Gillian Nave, Craig J. Sansonetti |
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| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Earth and Planetary Astrophysics (astro-ph.EP)
Physics Hollow-cathode lamp Accuracy and precision Atomic Physics (physics.atom-ph) business.industry Near-infrared spectroscopy FOS: Physical sciences Thorium chemistry.chemical_element Astronomy and Astrophysics law.invention Physics - Atomic Physics Wavelength Optics chemistry Space and Planetary Science law Ionization Emission spectrum business Spectroscopy Astrophysics - Instrumentation and Methods for Astrophysics Instrumentation and Methods for Astrophysics (astro-ph.IM) Astrophysics - Earth and Planetary Astrophysics |
| Popis: | We have made precise observations of a thorium-argon hollow cathode lamp emission spectrum in the region between 350 nm and 1175 nm using a high-resolution Fourier transform spectrometer. Our measurements are combined with results from seven previously published thorium line lists (Giacchetti et al. 1974; Zalubas & Corliss 1974; Zalubas 1976; Palmer & Engleman 1983; Engleman et al. 2003; Lovis & Pepe 2007; Kerber et al. 2008) to re-optimize the energy levels of neutral, singly-, and doubly-ionized thorium (Th I, Th II, and Th III). Using the optimized level values, we calculate accurate Ritz wavelengths for 19874 thorium lines between 250 nm and 5500 nm (40000 1/cm to 1800 1/cm). We have also found 102 new thorium energy levels. A systematic analysis of previous measurements in light of our new results allows us to identify and propose corrections for systematic errors in Palmer & Engleman (1983) and typographical errors and incorrect classifications in Kerber et al. (2008). We also found a large scatter in the thorium line list of Lovis & Pepe (2007). We anticipate that our Ritz wavelengths will lead to improved measurement accuracy for current and future spectrographs that make use of thorium-argon or thorium-neon lamps as calibration standards. 15 pages, 8 figures, 7 tables. Revised to remove spurious lines in tables 1 and 6. Full versions of tables 1, 5, 6 and 7 uploaded as ancillary files |
| Databáze: | OpenAIRE |
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