Stokes imaging polarimetry using image restoration at the Swedish 1-m Solar Telescope

TL;DR

This paper demonstrates high-resolution, high-sensitivity solar magnetic field imaging using advanced polarimetric techniques and image restoration at the Swedish 1-m Solar Telescope, revealing detailed magnetic structures.

Contribution

It introduces a novel imaging setup with high-speed cameras and a calibration routine enabling diffraction-limited solar polarimetry with improved sensitivity.

Findings

Dark-cores have weaker magnetic fields and lower inclination angles.

Magnetic field strength in faculae-striations is lower than in nearby faculae.

Achieved near diffraction-limited images with low noise levels.

Abstract

Aims: We aim to achieve high spatial resolution as well as high polarimetric sensitivity, using an earth-based 1m-class solar telescope, for the study of magnetic fine structure on the Sun. Methods: We use a setup with 3 high-speed, low-noise cameras to construct datasets with interleaved polarimetric states, particularly suitable for Multi-Object Multi-Frame Blind Deconvolution image restorations. We discuss the polarimetric calibration routine as well as various potential sources of error in the results. Results: We obtained near diffraction limited images, with a noise level of approximately 10^(-3) I(cont). We confirm that dark-cores have a weaker magnetic field and at a lower inclination angle with respect to the solar surface than the edges of the penumbral filament. We show that the magnetic field strength in faculae-striations is significantly lower than in other nearby parts of the faculae.