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

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F20%3A00534442" target="_blank" >RIV/67985815:_____/20:00534442 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.3847/1538-4357/ab8010" target="_blank" >https://doi.org/10.3847/1538-4357/ab8010</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/ab8010" target="_blank" >10.3847/1538-4357/ab8010</a>

Result language

angličtina

Original language name

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

Original language description

We perform plasma diagnostics, including that of the non-Maxwellian kappa-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 kappa. 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 kappa. 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 kappa < 3. These results were checked by calculating synthetic ratios using DEMs obtained as a function of kappa. Ratios predicted using the DEMs assuming kappa-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.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

<a href="/en/project/GA18-09072S" target="_blank" >GA18-09072S: Spectroscopy of non-thermal distributions and non-equilibrium ionization in the solar corona and transition region</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astrophysical Journal

ISSN

1538-4357

e-ISSN

—

Volume of the periodical

893

Issue of the periodical within the volume

1

Country of publishing house

US - UNITED STATES

Number of pages

19

Pages from-to

34

UT code for WoS article

000528728900001

EID of the result in the Scopus database

2-s2.0-85084832248