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High-resolution X-ray spectroscopy of late-type stars with CHANDRA
We have analyzed high-resolution (Δλ ≅ 0.06 Å) X-ray spectra in the region 6–180 Å of the coronae of the cool stars Capella, Procyon, and α Centauri. These stars were observed with the the CHANDRA Low Energy Transmission Grating Spectrometer (LETGS) between Sep. and Dec. 1999. Temperatures are deriv...
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Published in: | Advances in space research 2003, Vol.32 (10), p.2059-2065 |
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Main Authors: | , , , , |
Format: | Article |
Language: | English |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | We have analyzed high-resolution (Δλ ≅ 0.06 Å) X-ray spectra in the region 6–180 Å of the coronae of the cool stars Capella, Procyon, and α Centauri. These stars were observed with the the CHANDRA Low Energy Transmission Grating Spectrometer (LETGS) between Sep. and Dec. 1999. Temperatures are derived from line ratios of helium-like lines and long-wavelength iron lines. Electron densities are obtained for the relatively cooler (few MK) and more tenuous (⪅ 10
11 cm
−3) plasma components from the forbidden to intercombination line ratios in the helium-like triplets of O, N, and C and for the hotter (⪆ 5 MK) and denser (⪆ 10
12 cm
−3) components (such as occur in Capella) from the helium-like triplets of Mg and Si and the ratios of Fe XIX-Fe XXII 2ℓ-2ℓ′ lines above 90 Å. The implications of these results for the coronal structure are discussed. |
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ISSN: | 0273-1177 1879-1948 |
DOI: | 10.1016/S0273-1177(03)90645-4 |