Measurements of Photospheric and Chromospheric Magnetic Field Structures Associated with Chromospheric Heating over a Solar Plage Region

Abstract

In order to investigate the relation between magnetic structures and the signatures of heating in plage regions, we observed a plage region with the He I 1083.0 nm and Si I 1082.7 nm lines on 2018 October 3 using the integral field unit mode of the GREGOR Infrared Spectrograph (GRIS) installed at the GREGOR telescope. During the GRIS observation, the Interface Region Imaging Spectrograph (IRIS) obtained spectra of the ultraviolet Mg II doublet emitted from the same region. In the periphery of the plage region, within the limited field of view seen by GRIS, we find that the Mg II radiative flux increases with the magnetic field in the chromosphere with a factor of proportionality of 2.38 \times 10^4 erg cm^{-2} s^{-1} G^{-1}. The positive correlation implies that magnetic flux tubes can be heated by Alfv'en wave turbulence or by collisions between ions and neutral atoms relating to Alfv'en waves. Within the plage region itself, the radiative flux was large between patches of strong magnetic field strength in the photosphere, or at the edges of magnetic patches. On the other hand, we do not find any significant spatial correlation between the enhanced radiative flux and the chromospheric magnetic field strength or the electric current. In addition to the Alfv'en wave turbulence or collisions between ions and neutral atoms relating to Alfv'en waves, other heating mechanisms related to magnetic field perturbations produced by interactions of magnetic flux tubes could be at work in the plage chromosphere.

19 pages, 18 figures, 2 tables, accepted for publication in The Astrophysical Journal

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Cited by in corpus (9)

• Spatio-temporal analysis of chromospheric heating in a plage region
• First light of the Integral Field Unit of GRIS on the GREGOR solar telescope
• Tomography of a solar plage with the Tenerife Inversion Code
• Undetected Minority-polarity Flux as the Missing Link in Coronal Heating
• Constraining the systematics of (acoustic) wave heating estimates in the solar chromosphere
• Optimal spectral lines for measuring chromospheric magnetic fields
• Temperature diagnostics of chromospheric fibrils
• High-resolution observations of two pores with the integral field unit (IFU) of the GREGOR Infrared Spectrograph (GRIS)
• An iterative OLA method for inversion of solar spectropolarimetric data: I. Single and multiple variable inversions of thermodynamic quantities