Detail publikace

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

BOE, B. HABBAL, S. DRUCKMÜLLER, M. LANDI, E. KOURKCHI, E. DING, A. ŠTARHA, P. HUTTON, J.

Originální název

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

Typ

článek v časopise ve Web of Science, Jimp

Jazyk

angličtina

Originální abstrakt

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.

Klíčová slova

Sun, corona, solar wind, eclipse, coronal mass ejection, particle emission

Autoři

BOE, B.; HABBAL, S.; DRUCKMÜLLER, M.; LANDI, E.; KOURKCHI, E.; DING, A.; ŠTARHA, P.; HUTTON, J.

Vydáno

1. 6. 2018

Nakladatel

IOP PUBLISHING LTD, TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND

Místo

England

ISSN

0004-637X

Periodikum

ASTROPHYSICAL JOURNAL

Ročník

259

Číslo

2

Stát

Spojené státy americké

Strany od

105

Strany do

119

Strany počet

14

URL

http://iopscience.iop.org/article/10.3847/1538-4357/aabfb7/pdf

BibTex

@article{BUT148885,
  author="Benjamin {Boe} and Shadia Rifai {Habbal} and Miloslav {Druckmüller} and Enrico {Landi} and Ehsan {Kourkchi} and Adalbert {Ding} and Pavel {Štarha} and Joseph {Hutton}",
  title="The First Empirical Determination of the Fe10+ and Fe13+ Freeze-in Distances in the Solar Corona",
  journal="ASTROPHYSICAL JOURNAL",
  year="2018",
  volume="259",
  number="2",
  pages="105--119",
  doi="10.3847/1538-4357/aabfb7",
  issn="0004-637X",
  url="http://iopscience.iop.org/article/10.3847/1538-4357/aabfb7/pdf"
}