Vector Spectropolarimetry of Dark-cored Penumbral Filaments with Hinode
Bellot Rubio
ApJL, 2007, in press
BBSO High Resolution Observation
• Non-uniformity in sunspot penumbra
• The special term was defined by Scharmer et al., 2002
Physics
• Manifestation of Magnetic Flux Tubes (Sutterlin et al., 2004, Borrero 2007)
• Field-Free gaps (Spruit & Scharmer, 2006)
Observing Tool
• Hinode Solar Optical Telescope
--Spectropolarimeter
Stokes Q,U,V,I
Resolution of 0.3”
Comparison of a sunspot near the limb and at disk
center
Conclusion
Darker cores are 100-150G weaker
(are not field free)
Dark cores are more inclined (4 degrees)
Strong Evershed flow (6-7 km/s)
Limitation
• The structure is not fully resolved
• The Stokes inversion is not matured