CRISP Spectropolarimetric Imaging of Penumbral Fine Structure

Abstract

We discuss penumbral fine structure in a small part of a pore, observed with the CRISP imaging spectropolarimeter at the Swedish 1-m Solar Telescope (SST), close to its diffraction limit of 0.16 arcsec. Milne-Eddington inversions applied to these Stokes data reveal large variations of field strength and inclination angle over dark-cored penumbral intrusions and a dark-cored light bridge. The mid-outer part of this penumbra structure shows 0.3 arcsec wide spines, separated by 1.6 arcsec (1200 km) and associated with 30 deg inclination variations. Between these spines, there are no small-scale magnetic structures that easily can be be identified with individual flux tubes. A structure with nearly 10 deg more vertical and weaker magnetic field is seen midways between two spines. This structure is co-spatial with the brightest penumbral filament, possibly indicating the location of a convective upflow from below.

Accepted for publication in ApJL 17 Oct 2008. One Figure added

References in corpus (7)

• Stokes imaging polarimetry using image restoration at the Swedish 1-m Solar Telescope
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• Evidence of magnetic field wrapping around penumbral filaments
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Cited by in corpus (1)

• Coupling from the photosphere to the chromosphere and the corona