Vector spectropolarimetry of dark-cored penumbral filaments with Hinode

Abstract

We present spectropolarimetric measurements of dark-cored penumbral filaments taken with Hinode at a resolution of 0.3". Our observations demonstrate that dark-cored filaments are more prominent in polarized light than in continuum intensity. Far from disk center, the Stokes profiles emerging from these structures are very asymmetric and show evidence for magnetic fields of different inclinations along the line of sight, together with strong Evershed flows of at least 6-7 km/s. In sunspots closer to disk center, dark-cored penumbral filaments exhibit regular Stokes profiles with little asymmetries due to the vanishing line-of-sight component of the horizontal Evershed flow. An inversion of the observed spectra indicates that the magnetic field is weaker and more inclined in the dark cores as compared with the surrounding bright structures. This is compatible with the idea that dark-cored filaments are the manifestation of flux tubes carrying hot Evershed flows.

Accepted for publication in ApJ Letters. Use the Postscript version for high quality figures

References in corpus (3)

• Magnetostatic penumbra models with field-free gaps
• Two-dimensional spectroscopy of a sunspot. III Thermal and kinematic structure of the penumbra at 0.5"
• The structure of sunspot penumbrae IV. MHS equilibrium for penumbral flux tubes and the origin of dark core penumbral filaments and penumbral grains

Cited by in corpus (13)

• CRISP Spectropolarimetric Imaging of Penumbral Fine Structure
• Stokes imaging polarimetry using image restoration at the Swedish 1-m Solar Telescope
• Super-strong Magnetic Field in Sunspots
• Three-dimensional structure of a sunspot light bridge
• Detection of sea-serpent field lines in sunspot penumbrae
• Evidence of magnetic field wrapping around penumbral filaments
• Heat transfer in sunspot penumbrae. Origin of dark-cored penumbral filaments
• Sunspots: from small-scale inhomogeneities towards a global theory
• Models and Observations of Sunspot Penumbrae
• A three-dimensional view of the thermal structure in a super-penumbral canopy
• Spectropolarimetery of umbral fine structures from Hinode: Evidence for magnetoconvection
• Multiple Stokes I inversions to infer magnetic fields in the spectral range around Cr I 5782 Å
• High-resolution spectro-polarimetry of a flaring sunspot penumbra