DKIST observations of the fine-scale chromospheric structures

The strongly coupled hydrodynamic, magnetic and radiation properties of the plasma in the solar chromosphere makes it a region of the Sun’s atmosphere that is poorly understood. Despite a wealth of recent observations and numerical models, disentangling the processes that drive the chromospheric fine structure and dynamics remains one of the most compelling problems in solar physics. We use data of a plage region obtained with the high-resolution VBI imager equipped with the Hbeta filter on DKIST, to investigate fine-scale features of the chromosphere such as fibrils and rapid excursions. The large aperture and state-of-the-art instrumentation afforded by DKIST, allowed us to observe a large field-of-view at a spatial resolution of approximately 20 km in some instance. To aid the interpretation of the DKIST filtergraph, we also analyzed Hbeta scans obtained with the CHROMospheric Imaging Spectrometer (CHROMIS) on the Swedish Solar Telescope. The CHROMIS data were integrated over the wavelength range covered by the VBI transmission filter to reproduce the corresponding chromospheric scene. The analysis of spectral properties, such as enhanced line widths and Doppler shifts, can explain the high contrast of the chromospheric fine-scale features relative to the background. Our results demonstrate that Hbeta is an excellent diagnostic to identify and track the enigmatic fine-scale structure of the chromosphere.