Mapping the longitudinal magnetic field in the atmosphere of an active region plage from the inversion of the near-ultraviolet CLASP2.1 spectropolarimetric data

TL;DR

This study uses spectropolarimetric data and inversion techniques to map the magnetic field and atmospheric properties in an active region plage, revealing correlations between magnetic flux, heating, and chromospheric structure.

Contribution

It introduces a novel application of the HanleRT Tenerife Inversion Code to near-ultraviolet spectropolarimetric data for detailed magnetic and atmospheric mapping.

Findings

Larger temperature and electron density in plage and superpenumbra regions.

Magnetic field structures correlate with brightness and heating patterns.

Different heating mechanisms suggested for plage and superpenumbra regions.

Abstract

We apply the HanleRT Tenerife Inversion Code to the spectro-polarimetric observations obtained by the Chromospheric LAyer SpectroPolarimeter. This suborbital space experiment measured the variation with wavelength of the four Stokes parameters in the near-ultraviolet spectral region of the Mg II h & k lines over a solar disk area containing part of an active region plage and the edge of a sunspot penumbra. We infer the stratification of the temperature, the electron density, the line of-sight velocity, the micro-turbulent velocity, and the longitudinal component of the magnetic field from the observed intensity and circular polarization profiles. The inferred model atmosphere shows larger temperature and electron density in the plage and the superpenumbra regions than in the quiet regions. The shape of the plage region in terms of its brightness is similar to the pattern of the inferred longitudinal component of the magnetic field in the chromosphere, as well as to that of the overlying moss observed by AIA in the 171 A band, which suggests a similar magnetic origin for the heating in both the plage and the moss region. Moreover, this heating is particularly significant in the regions with larger inferred magnetic flux. In contrast, in the superpenumbra, the regions with larger electron density and temperature are usually found in between these regions with larger magnetic flux, suggesting that the details of the heating mechanism in the chromosphere of the superpenumbra may be different to those in the plage, but with the magnetic field still playing a key role.