Periodic variations of the Ba II 4554 Å and Ca II 8542 Å line profiles in coronal holes
| Autor: | N. I. Kobanov, D. Yu. Kolobov, S. A. Chupin |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Physics
010504 meteorology & atmospheric sciences Coronal hole Astronomy and Astrophysics Astrophysics Computer Science::Computational Geometry Solar atmosphere 01 natural sciences Molecular physics Spectral line Space and Planetary Science Physics::Space Physics 0103 physical sciences Thermal Astrophysics::Solar and Stellar Astrophysics 010303 astronomy & astrophysics 0105 earth and related environmental sciences Line (formation) |
| Zdroj: | Astronomy Letters. 42:55-62 |
| ISSN: | 1562-6873 1063-7737 |
| DOI: | 10.1134/s1063773716010047 |
| Popis: | The oscillations of the half-width of the Ba II 4554 Ǻ and Ca II 8542 Ǻ spectral lines have been analyzed using observations at the base of solar coronal holes (CHs). The observed variations (~50 m Ǻ for Ca II and ~4 m Ǻ for Ba II) exceed considerably the thermal broadenings of these lines calculated from the measured intensity oscillations, suggesting their nonthermal nature. We point out a number of observational facts that hamper an unambiguous interpretation of the periodic Ba II and Ca II profile variations solely by the manifestation of torsional Alfve´ n waves in the lower solar atmosphere. |
| Databáze: | OpenAIRE |
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