2024/02/15 by T. A. Schad, Thomas A. Schad, Schad, T. A. +21 · 1 voice · 1 citation
Engineering · Physics and Astronomy · #Calibration and Measurement Techniques #FOS: Physical sciences #Solar and Stellar Astrophysics (astro-ph.SR) #astro-ph.SR
paper · pdf · doi:10.48550/arxiv.2402.09632
openalex publication_date 2024/02/15 · arxiv published 2024/02/15 · arxiv updated 2024/02/15 · openalex created_date 2024/02/18 · openalex updated_date 2026/07/28
We report commissioning observations of the Si X 1430 nm solar coronal line observed coronagraphically with the Cryogenic Near-Infrared Spectropolarimeter (Cryo-NIRSP) at the National Science Foundation's Daniel K. Inouye Solar Telescope (DKIST). These are the first known spatially resolved observations of this spectral line, which has strong potential as a coronal magnetic field diagnostic. The observations target a complex active region located on the solar northeast limb on 4 March 2022. We present a first analysis of this data, which extracts the spectral line properties through a careful treatment of the variable atmospheric transmission that is known to impact this spectral window. Rastered images are created and compared with EUV observations from the SDO/AIA instrument. A method for estimating the electron density from the Si X observations is then demonstrated that makes use of the forbidden line's density-sensitive emissivity and an emission-measure analysis of the SDO/AIA bandpass observations. In addition, we derive an effective temperature and non-thermal line width across the region. This study informs the calibration approaches required for more routine observations of this promising diagnostic line.