Fine-Scale Structure of Solar Polar Faculae and their relation to Magnetic Patches
Abstract
The fine-scale structure and dynamics of solar polar faculae were studied using Hinode/SOT spectro-polarimetric and filtergraphic observations at polar regions. It is revealed that polar magnetic patches of large flux have substructures, with a few small faculae in the much larger patches. It was also found that faculae tend to have higher intrinsic magnetic field strengths compared with the non-facular regions inside the associated magnetic patches. G-band images reveal much thinner facular structures of close to 0.1 arcsec and the faculae appear as a cluster of thin tapered tube-like structures; individual size is about 0.2 x 0.5 arcsec, reaching the maximum closer mid-way to the limb, are likely projected on the limb-side neighboring granules with center-ward dark lanes. Typical lifetime of each facular elements is about five minutes, showing side-way motion during the life. Corresponding bright fine elongated structures are seen in Ca II H, although such structures are more numerous and therefore there does not always exist one-to-one correspondence of Ca II H bright structures with the G-band facular elements. In H-alpha and Na I D line wing, fibril structure emanating limb-ward from the faulae and Ca II H bright regions. Those facts imply that the polar faculae appear in the root of intense vertically-oriented thin magnetic flux tubes which are consistent with the result from the magnetic properties reduced from the spectro-polarimetry. Those results suggest that the Spruit's hot wall effect explains the appearance of faculae in intense vertically oriented flux tube whose formation is dynamically changing.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2014
- Bibcode:
- 2014AGUFMSH31C..07S
- Keywords:
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- 7507 Chromosphere;
- 7509 Corona;
- 7519 Flares;
- 7524 Magnetic fields