Broad Non-Gaussian Fe XXIV Line Profiles in the Impulsive Phase of the 2017 September 10 X8.3-class Flare Observed by Hinode/EIS

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F18%3A00495420" target="_blank" >RIV/67985815:_____/18:00495420 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.3847/1538-4357/aad62d" target="_blank" >http://dx.doi.org/10.3847/1538-4357/aad62d</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/aad62d" target="_blank" >10.3847/1538-4357/aad62d</a>

Result language

angličtina

Original language name

Broad Non-Gaussian Fe XXIV Line Profiles in the Impulsive Phase of the 2017 September 10 X8.3-class Flare Observed by Hinode/EIS

Original language description

We analyze the spectra of high-temperature Fe XXIV lines observed by the Hinode/Extreme-Ultraviolet Imaging Spectrometer (EIS) during the impulsive phase of the X8.3-class flare on 2017 September 10. The line profiles are broad, show pronounced wings, and clearly depart from a single-Gaussian shape. The lines can be well fitted with kappa distributions, with values of kappa varying between approximate to 1.7 and 3. The regions where we observe the non-Gaussian profiles coincide with the location of high-energy (approximate to 100-300 keV) hard X-ray (HXR) sources observed by RHESSI, suggesting the presence of particle acceleration or turbulence, also confirmed by the observations of nonthermal microwave sources with the Expanded Owens Valley Solar Array at and above the HXR loop-top source. We also investigate the effect of taking into account t distributions in the temperature diagnostics based on the ratio of the Fe XXIII lambda 263.76 and Fe XXIV lambda 255.1 EIS lines. We found that these lines can be formed at much higher temperatures than expected (up to log(T[K]) approximate to 7.8) if departures from Maxwellian distributions are taken into account. Although larger line widths are expected because of these higher formation temperatures, the observed line widths still imply nonthermal broadening in excess of 200 km s(-1). The nonthermal broadening related to HXR emission is better interpreted by turbulence than by chromospheric evaporation.

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

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2018

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

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Volume of the periodical

864

Issue of the periodical within the volume

1

Country of publishing house

US - UNITED STATES

Number of pages

15

Pages from-to

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UT code for WoS article

000443244200014

EID of the result in the Scopus database

2-s2.0-85053157797