Returning magnetic flux in sunspot penumbrae

Abstract

We study the presence of reversed polarity magnetic flux in sunspot penumbra. We applied a new regularized method to deconvolve spectropolarimetric data observed with the spectropolarimeter SP onboard Hinode. The new regularization is based on a principal component decomposition of the Stokes profiles. The resulting Stokes profiles were inverted to infer the magnetic field vector using SIR. We find, for the first time, reversed polarity fields at the border of many bright penumbral filaments in the whole penumbra.

5 pages, 5 figures, accepted for publication in A&A Letters

References in corpus (5)

• Penumbral structure and outflows in simulated sunspots
• The intensity contrast of solar granulation: comparing Hinode SP results with MHD simulations
• Spatially coupled inversion of spectro-polarimetric image data I: Method and first results
• Sunspots: from small-scale inhomogeneities towards a global theory
• Models and Observations of Sunspot Penumbrae

Cited by in corpus (50)

• Inversion of the radiative transfer equation for polarized light
• The European Solar Telescope
• Structure of sunspot penumbral filaments: a remarkable uniformity of properties
• Radiative diagnostics in the solar photosphere and chromosphere
• Enhancing SDO/HMI images using deep learning
• Multi-height observations of magnetoacoustic cut-off frequency in a sunspot atmosphere
• Opposite polarity field with convective downflow and its relation to magnetic spines in a sunspot penumbra
• Stokes Inversion based on Convolutional Neural Networks
• A method for global inversion of multi-resolution solar data
• Three-dimensional structure of a sunspot light bridge
• Depth-dependent global properties of a sunspot observed by Hinode using the Solar Optical Telescope/Spectropolarimeter
• Sparse inversion of Stokes profiles. I. Two-dimensional Milne-Eddington inversions
• Deep probing of the photospheric sunspot penumbra: no evidence for magnetic field-free gaps
• IRIS observations of magnetic interactions in the solar atmosphere between pre-existing and emerging magnetic fields. I. Overall evolution
• Transition-Region/Coronal Signatures and Magnetic Setting of Sunspot Penumbral Jets: {\it Hinode} (SOT/FG), Hi-C and {\it SDO}/AIA Observations
• Formation of the penumbra and start of the Evershed flow
• Spatial deconvolution of spectropolarimetric data: an application to quiet Sun magnetic elements
• Observationally based models of penumbral microjets
• Inferring Vector Magnetic Fields from Stokes Profiles of GST/NIRIS Using a Convolutional Neural Network
• A new MHD-assisted Stokes inversion technique
• Magnetic fields of opposite polarity in sunspot penumbrae
• Lateral downflows in sunspot penumbral filaments and their temporal evolution
• Vertical magnetic field gradient in the photospheric layers of sunspots
• The problem of the height dependence of magnetic fields in sunspots
• Upper Chromospheric Magnetic Field of a Sunspot Penumbra: Observations of Fine Structure
• Evidence of Twisting and Mixed-polarity Solar Photospheric Magnetic Field in Large Penumbral Jets: IRIS and Hinode Observations
• Signatures of magnetic reconnection at the footpoints of fan shape jets on a light bridge driven by photospheric convective motions
• Three-dimensional magnetic structure of a sunspot: comparison of the photosphere and upper chromosphere
• Anomalous flows in a sunspot penumbra
• The small-scale structure of photospheric convection retrieved by a deconvolution technique applied to Hinode/SP data
• Magnetic topology of the north solar pole
• Properties of the Umbral Filament Observed in Active Region NOAA 12529
• Emergence of small-scale magnetic flux in the quiet Sun
• Analysis of a spatially deconvolved solar pore
• Magnetic Properties and Flow Angle of the Inverse Evershed Flow at Its Downflow Points
• Signatures of ubiquitous magnetic reconnection in the deep atmosphere of sunspot penumbrae
• Mapping the hidden magnetic field of the quiet Sun
• Penumbral decay observed in active region NOAA 12585
• Analysis of spatially deconvolved polar faculae
• Signatures of the impact of flare ejected plasma on the photosphere of a sunspot light-bridge
• Penumbral thermal structure below the visible surface
• Long-Term Evolution of Three Light Bridges Developed on the Same Sunspot
• Inversion of Stokes Profiles with Systematic Effects
• The dark side of penumbral microjets: Observations in Hα
• Small-scale magnetic and velocity inhomogeneities in a sunspot light bridge
• Detection of emission in the Si i 1082.7 nm line core in sunspot umbrae
• Chromospheric plasma ejection above a pore
• Neural translation for Stokes inversion and synthesis
• The association between sunspot magnetic fields and superpenumbral fibrils
• Opposite polarity magnetic field and convective downflows in a simulated sunspot penumbra