Spectral line broadening and asymmetry observed with DKIST-ViSP

In the quiet region on the solar surface, turbulent convective motions of granulation play an important role in creating small-scale magnetic structures as well as the energy injection into the upper atmosphere. The turbulent nature can be studied using spectral line profiles, especially their line width, that contain information on flow fields smaller than the spatial resolution of the instrument. Ishikawa et al. (2020) found transient enhancements of the spectral line widths of the Fe I 6301.5 Angstrom line obtained with the Hinode Solar Optical Telescope, whose spatial resolution is 0.32". They suggested that the wide spectral line widths can be a signature of turbulent motions on scales smaller than the spatial resolution or velocity gradients along the line of sight. The Visible Spectro-Polarimeter (ViSP) of the Daniel K. Inouye Solar Telescope (DKIST) can achieve an unpreceded resolution much better than 0.1" and is expected to provide access to the smallest-scale turbulence and its interaction with magnetic fields. In Operations Commissioning Phase Cycle 1(OCP1), we observed a quiet region at the disk center with repetitive scans with a cadence of 73 seconds covering a field-of-view of 1.64" x 76.8" on 15th April 2022. We examined the spatial and temporal variations of the spectral line widths of the Fe I 6301.5 Angstrom line. Some of the line width enhancements were associated with magnetic fields, but some did not have a clear association with magnetic fields.