Structure and Dynamics of Cool Flare Loops Observed by the Interface Region Imaging Spectrograph

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F17%3A00479454" target="_blank" >RIV/67985815:_____/17:00479454 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.3847/1538-4357/aa7d4e" target="_blank" >http://dx.doi.org/10.3847/1538-4357/aa7d4e</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/aa7d4e" target="_blank" >10.3847/1538-4357/aa7d4e</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Structure and Dynamics of Cool Flare Loops Observed by the Interface Region Imaging Spectrograph

Popis výsledku v původním jazyce

Flare loops were well observed with the Interface Region Imaging Spectrograph (IRIS) during the gradual phase of two solar flares on 2014 March 29 and 2015 June 22. Cool flare loops are visible in various spectral lines formed at chromospheric and transition-region temperatures and exhibit large downflows which correspond to the standard scenario. The principal aim of this work is to analyze the structure and dynamics of cool flare loops observed in Mg II lines. Synthetic profiles of the Mg II h line are computed using the classical cloud model and assuming a uniform background intensity. In this paper, we study novel IRIS NUV observations of such loops in Mg II h and k lines and also show the behavior of hotter lines detected in the FUV channel. We obtained the spatial evolution of the velocities: near the loop top, the flow velocities are small and they are increasing toward the loop legs. Moreover, from slit-jaw image (SJI) movies, we observe some plasma upflows into the loops, which are also detectable in Mg II spectra. The brightness of the loops systematically decreases with increasing flow velocity, and we ascribe this to the effect of Doppler dimming, which works for Mg II lines. Emission profiles of Mg II were found to be extremely broad, and we explain this through the large unresolved non-thermal motions.

Název v anglickém jazyce

Structure and Dynamics of Cool Flare Loops Observed by the Interface Region Imaging Spectrograph

Popis výsledku anglicky

Flare loops were well observed with the Interface Region Imaging Spectrograph (IRIS) during the gradual phase of two solar flares on 2014 March 29 and 2015 June 22. Cool flare loops are visible in various spectral lines formed at chromospheric and transition-region temperatures and exhibit large downflows which correspond to the standard scenario. The principal aim of this work is to analyze the structure and dynamics of cool flare loops observed in Mg II lines. Synthetic profiles of the Mg II h line are computed using the classical cloud model and assuming a uniform background intensity. In this paper, we study novel IRIS NUV observations of such loops in Mg II h and k lines and also show the behavior of hotter lines detected in the FUV channel. We obtained the spatial evolution of the velocities: near the loop top, the flow velocities are small and they are increasing toward the loop legs. Moreover, from slit-jaw image (SJI) movies, we observe some plasma upflows into the loops, which are also detectable in Mg II spectra. The brightness of the loops systematically decreases with increasing flow velocity, and we ascribe this to the effect of Doppler dimming, which works for Mg II lines. Emission profiles of Mg II were found to be extremely broad, and we explain this through the large unresolved non-thermal motions.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

<a href="/cs/project/GA16-18495S" target="_blank" >GA16-18495S: Pokročilý výzkum Slunce se satelitem IRIS</a><br>

Návaznosti

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

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

Astrophysical Journal

ISSN

0004-637X

e-ISSN

—

Svazek periodika

845

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

15

Strana od-do

"30/1"-"30/15"

Kód UT WoS článku

000407329800009

EID výsledku v databázi Scopus

2-s2.0-85029161058