The First Empirical Determination of the Fe10+ and Fe13+ Freeze-in Distances in the Solar Corona

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26210%2F18%3APU128479" target="_blank" >RIV/00216305:26210/18:PU128479 - isvavai.cz</a>

Result on the web

<a href="http://iopscience.iop.org/article/10.3847/1538-4357/aabfb7/pdf" target="_blank" >http://iopscience.iop.org/article/10.3847/1538-4357/aabfb7/pdf</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/aabfb7" target="_blank" >10.3847/1538-4357/aabfb7</a>

Result language

angličtina

Original language name

The First Empirical Determination of the Fe10+ and Fe13+ Freeze-in Distances in the Solar Corona

Original language description

Heavy ions are markers of the physical processes responsible for the density and temperature distribution throughout the fine-scale magnetic structures that define the shape of the solar corona. One of their properties, whose empirical determination has remained elusive, is the "freeze-in" distance (R-f) where they reach fixed ionization states that are adhered to during their expansion with the solar wind. We present the first empirical inference of R-f for Fe10+ and Fe13+ derived from multi-wavelength imaging observations of the corresponding Fe XI (Fe10+) 789.2 nm and Fe XIV (Fe13+) 530.3 nm emission acquired during the 2015 March 20 total solar eclipse. We find that the two ions freeze-in at different heliocentric distances. In polar coronal holes (CHs)R-f is around 1.45 R-circle dot for Fe10+ and below 1.25 R-circle dot for Fe13+. Along open field lines in streamer regions, R-f ranges from 1.4 to 2 R-circle dot for Fe10+ and from 1.5 to 2.2 R-circle dot for Fe13+. These first empirical R-f values: (1) reflect the differing plasma parameters between CHs and streamers and structures within them, including prominences and coronal mass ejections; (2) are well below the currently quoted values derived from empirical model studies; and (3) place doubt on the reliability of plasma diagnostics based on the assumption of ionization equilibrium beyond 1.2 R-circle dot.

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

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OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

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Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2018

Confidentiality

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

Name of the periodical

ASTROPHYSICAL JOURNAL

ISSN

0004-637X

e-ISSN

1538-4357

Volume of the periodical

259

Issue of the periodical within the volume

2

Country of publishing house

US - UNITED STATES

Number of pages

14

Pages from-to

105-119

UT code for WoS article

000434264500009

EID of the result in the Scopus database

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