Electron DENSITY of active region outflows measured by the EUV imaging spectrometer on board HINODE
- National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
In order to better understand the nature of active region outflows, the electron density was measured by using a density-sensitive line pair, Fe xiv 264.78 Å/274.20 Å. Because coronal line profiles of the outflow region are composed of a major component with a Doppler shift of ⩽10 km s{sup −1} and a minor component (enhanced blue wing, EBW) blueshifted by up to 100 km s{sup −1}, we extracted EBW from the line profiles through double-Gaussian fitting. We tried applying the simultaneous fitting to those two Fe xiv lines with several physical restrictions. Electron density for both components (n{sub Major} and n{sub EBW}, respectively) was calculated by referring to the theoretical intensity ratio as a function of electron density as per the CHIANTI database. We studied six locations in the outflow regions around NOAA AR10978. The average electron density was n{sub Major}=10{sup 9.16±0.16} cm{sup −3} and n{sub EBW}=10{sup 8.74±0.29} cm{sup −3}. The magnitude relationship between n{sub Major} and n{sub EBW} was the opposite in the eastern and western outflow regions. The column depth was also calculated for each component, which leads to the result that the outflows possess only a small fraction (∼0.1) in the eastern region, whereas they dominate over the major component in the line profiles by a factor of five in the western region. When taking into account the extended coronal structures, the western region can be thought to represent the mass leakage. In contrast, we suggest a possibility that the eastern region actually contributes to mass supply to coronal loops.
- OSTI ID:
- 22883159
- Journal Information:
- Astrophysical Journal, Vol. 805, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Since 2009, the country of publication for this journal is the UK.; ISSN 0004-637X
- Country of Publication:
- United Kingdom
- Language:
- English
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