Unresolved Mixed Polarity Magnetic Fields at Flux Cancellation Site in Solar Photosphere at 0".3 Spatial Resolution

TL;DR

This study investigates unresolved mixed polarity magnetic fields at flux cancellation sites in the solar photosphere, revealing that anomalous polarization signals are due to unresolved magnetic structures rather than flux removal, at a resolution of 0.3 arcseconds.

Contribution

It demonstrates that anomalous Stokes V profiles are caused by unresolved opposite-polarity magnetic elements, challenging previous interpretations of flux removal processes.

Findings

Anomalous Stokes V profiles are explained by unresolved magnetic structures.

Unresolved mixed polarity fields are present at flux cancellation sites.

Flux removal likely occurs below the current resolution limit.

Abstract

This is a follow-up investigation of a magnetic-flux cancellation event at a polarity inversion line (PIL) on the Sun observed with the spectropolarimeter on board Hinode. Anomalous circular polarization (Stokes V) profiles are observed in the photosphere along the PIL at the cancellation sites. Kubo et al. (2010) previously reported that the theoretically expected horizontal fields between the canceling opposite-polarity magnetic elements in this event are not detected at granular scales. We show that the observed anomalous Stokes V profiles are reproduced successfully by adding the nearly symmetric Stokes V profiles observed at pixels immediately adjacent to the PIL. This result suggests that these observed anomalous Stokes V profiles are not indications of a flux removal process, but are the result of either a mixture of unresolved, opposite-polarity magnetic elements or the unresolved width of the PIL, at an estimated resolution element of about 0".3. The hitherto undetected flux removal process accounting for the larger-scale disappearance of magnetic flux during the observing period is likely to also fall below resolution.