X-Ray Spectroscopic Investigation of the Coronal Structure of Capella
Abstract
The binary system Capella (G6 III + F9 III) has been observed on 1979 March 15 and on 1980 March 15 17 with the Objective Grating Spectrometer (OGS) onboard the Einstein Observatory. The spectrum measured with the 1000 l/mm grating covers the range 5 30 Å with a resolution < 1 Å. The spectra show evidence for a bimodal temperature distribution of emission measure in an optically thin plasma with one component ∼ 5 million degrees and the other one ∼10 million degrees. Spectral features can be identified with line emissions from O VIII, Fe XVII, Fe XVIII, Fe XXIV, and Ne X ions. Good spectral fits have been obtained assuming standard cosmic abundances. The data are interpreted in terms of emission from hot static coronal loops rather similar to the magnetic arch structures found on the Sun. It is shown that the conditions required by this model exist on Capella. Mean values of loop parameters are derived for both temperature components.
- Publication:
-
Space Science Reviews
- Pub Date:
- March 1981
- DOI:
- 10.1007/BF01246017
- Bibcode:
- 1981SSRv...30..185G
- Keywords:
-
- Binary Stars;
- Stellar Spectrophotometry;
- Stellar Structure;
- X Ray Sources;
- X Ray Spectroscopy;
- Abundance;
- Emission Spectra;
- Gratings (Spectra);
- Iron;
- Line Spectra;
- Neon;
- Spectral Resolution;
- Stellar Temperature;
- Temperature Distribution;
- Thermal Plasmas;
- Astrophysics