[Loops] new paper

[lorincik]

Dear all,

you might be interested in our new paper Lörinčík et al. 2020:

Title: Plasma Diagnostics from Active Region and Quiet-Sun Spectra 
Observed by Hinode/EIS: Quantifying the Departures from a Maxwellian 
Distribution

Abstract: We perform plasma diagnostics, including that of the 
non-Maxwellian κ-distributions, in several structures observed in the 
solar corona by the Extreme-Ultraviolet Imaging Spectrometer (EIS) on 
board the Hinode spacecraft. To prevent uncertainties due to the 
in-flight calibration of EIS, we selected spectral atlases observed 
shortly after the launch of the mission. One spectral atlas contains an 
observation of an active region, while the other is an off-limb 
quiet-Sun region. To minimize the uncertainties of the diagnostics, we 
rely only on strong lines and average the signal over a spatial area 
within selected structures. Multiple plasma parameters are diagnosed, 
such as the electron density, the differential emission measure, and the 
non-Maxwellian parameter κ. To do that, we use a simple, well-converging 
iterative scheme based on refining the initial density estimates via the 
differential emission measure (DEM) and κ. We find that while the 
quiet-Sun spectra are consistent with a Maxwellian distribution, the 
coronal loops and moss observed within the active region are strongly 
non-Maxwellian with κ lap 3. These results were checked by calculating 
synthetic ratios using DEMs obtained as a function of κ. Ratios 
predicted using the DEMs assuming κ-distributions converged to the 
ratios observed in the quiet Sun and coronal loops. To our knowledge, 
this work presents a strong evidence of the presence of different 
electron distributions between two physically distinct parts of the 
solar corona.

Links:
https://arxiv.org/abs/2003.07091
https://iopscience.iop.org/article/10.3847/1538-4357/ab8010

Sincerely,

Juraj Lörinčík