Enhanced Coronal Heating Detected across the Prominence–Corona Boundary Using DKIST/Cryo-NIRSP Spectropolarimetric Observations
Year: 2026
Type: article
Abstract: We report on the first inference of the nonthermal energy flux and subsequent heating across the prominence–corona transition region (PCTR) and a nearby active region (NOAA AR 13875) using DKIST/Cryo-NIRSP spectropolarimetric measurements. The observations were acquired on 2024 October 20 and 21, in the Fe xiii 1074.7 and 1079.8 nm lines as well as in He i 1083 nm. The nonthermal component of the Gaussian line broadening was extracted from the Fe xiii 1074.7 nm observations, assuming a locally isothermal plasma. Electron density was inferred from the Fe xiii 1079.8 nm/1074.7 nm line ratio. The full Stokes polarimetry enabled the modeling of a partial coronal magnetogram, which offered constraints on an empirical model to infer magnetic field strength. The inferred density, nonthermal line widths, and magnetic field strength enabled the calculation of wave energy density, Alfvén velocity, Alfvén energy flux, and volumetric heating rates in the target region. The prominence shroud appeared as a narrow and highly dynamic layer between the prominence and the overlying cavity. Each structure exhibited a different exponential volumetric heating decay rate as a function of coronal height, with e-folding length scales of 9.1 ± 1.9 Mm, 58.1 ± 5.4 Mm, and 45.1 ± 2.9 Mm, respectively, in the PCTR, overlying cavity, and nearby AR. Additionally, we found that the prominence exhibits phase-shifted, wavelike velocity and intensity structures in the He i 1083 nm line, suggesting magnetoacoustic waves may be responsible for damping and local heating around the PCTR.
Source: The Astrophysical Journal
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
OpenAlex ID: W7221071429