A NEW CALCULATION OF Ne IX LINE DIAGNOSTICS
Autor: | Nancy S. Brickhouse, Randall K. Smith, Kate Kirby, Guo-Xin Chen |
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Rok vydání: | 2009 |
Předmět: |
High Energy Astrophysical Phenomena (astro-ph.HE)
Physics Spectrometer FOS: Physical sciences Astronomy and Astrophysics Ion Space and Planetary Science Emissivity Spontaneous emission Atomic physics Astrophysics - High Energy Astrophysical Phenomena Collisional excitation Excitation Recombination Line (formation) |
Zdroj: | The Astrophysical Journal. 700:679-683 |
ISSN: | 1538-4357 0004-637X |
DOI: | 10.1088/0004-637x/700/1/679 |
Popis: | We describe the effect that new atomic calculations, including fully-relativistic R-matrix calculations of collisional excitation rates and level-specific dielectronic and radiative recombination rates, have on line ratios from the astrophysically significant ion Ne IX. The new excitation rates systematically change some predicted Ne IX line ratios by 25% at temperatures at or below the temperature of maximum emissivity (4x10^6 K), while the new recombination rates lead to systematic changes at higher temperatures. The new line ratios are shown to agree with observations of Capella and sigma^2 CrB significantly better than older line ratios, showing that 25-30% accuracy in atomic rates is inadequate for high-resolution X-ray observations from existing spectrometers. Comment: 5 pages, 6 figures |
Databáze: | OpenAIRE |
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