Presentation #212.22 in the session “Solar Physics Division (SPD): Instrumentation and Active Regions”.
The strongest quasi-steady heating in the solar atmosphere occurs in the active chromosphere and in particular within plage regions. Our aim is to investigate the relation between magnetic structures and the signatures of heating in the plage regions so as to clarify what mechanisms are at work. We observed a plage region in NOAA active region 12723 in the near infrared He I triplet and Si I 1082.7 nm on 2018 October 3 using the Integral Field Unit mode of the GREGOR Infrared Spectrograph (GRIS) installed at the GREGOR telescope. At the same time, the Interface Region Imaging Spectrograph (IRIS) obtained spectra in the ultra-violet Mg II h & k doublet emitted from the same region. We applied the HAnle and ZEeman Light v2.0 inversion code (HAZEL v2.0) to the GRIS data to infer the photospheric and chromospheric magnetic field. We find that the radiative flux of the Mg II was large between patches of strong magnetic field strength in the photosphere, or at edges of the magnetic patches. On the other hand, the spatial correspondences between the Mg II flux and the magnetic field strength in the chromosphere and between the Mg II flux and the electric current are not so clear. In conclusion, chromospheric heatings in the plage region can be related to magnetic field perturbations produced by interactions of magnetic flux tubes.