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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

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

Rok uplatnění

2018

Kód důvěrnosti údajů

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

Název periodika

Astrophysical Journal

ISSN

1538-4357

e-ISSN

—

Svazek periodika

864

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

15

Strana od-do

—

Kód UT WoS článku

000443244200014

EID výsledku v databázi Scopus

2-s2.0-85053157797