DKIST unveils the serpentine topology of quiet Sun magnetism in the photosphere

TL;DR

This paper presents the highest resolution spectropolarimetric observations of the quiet Sun, revealing complex small-scale magnetic structures and field strengths up to 2 kG, advancing understanding of quiet Sun magnetism.

Contribution

First high-resolution spectropolarimetric data of quiet Sun revealing detailed magnetic topology and field strengths, including complex polarity changes and magnetic loops.

Findings

Identified 53 small-scale magnetic elements, including loops and patches.

Detected magnetic field strengths up to 2 kG in intergranular lanes.

Observed complex Stokes profiles and polarity changes over small spatial scales.

Abstract

We present the first quiet Sun spectropolarimetric observations obtained with the Visible SpectroPolarimeter (ViSP) at the $4-$m Daniel K. Inouye Solar Telescope (DKIST). We recorded observations in a wavelength range that includes the magnetically sensitive Fe I $6301.5/6302.5$ $\AA$ doublet. With an estimated spatial resolution of 0.08'', this represents the highest spatial resolution full-vector spectropolarimetric observations ever obtained of the quiet Sun. We identified $53$ small-scale magnetic elements, including $47$ magnetic loops and $4$ unipolar magnetic patches, with linear and circular polarisation detected in all of them. Of particular interest is a magnetic element in which the polarity of the magnetic vector appears to change three times in only $400$ km and which has linear polarisation signals throughout. We find complex Stokes $V$ profiles at the polarity inversion lines of magnetic loops and discover degenerate solutions, as we are unable to conclusively determine whether these arise due to gradients in the atmospheric parameters or smearing of opposite polarity signals. We analyse a granule which notably has linear and circular polarisation signals throughout, providing an opportunity to explore its magnetic properties. On this small scale we see the magnetic field strength range from $25$ G at the granular boundary to $2$ kG in the intergranular lane (IGL), and sanity check the values with the weak and strong field approximations. A value of $2$ kG in the IGL is among the highest measurements ever recorded for the internetwork.