Comparison of coronal hole and quiet-Sun chromosphere using IRIS Mg II h and k observations of polar off-limb regions

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F25%3A00619110" target="_blank" >RIV/67985815:_____/25:00619110 - isvavai.cz</a>

Výsledek na webu

<a href="https://hdl.handle.net/11104/0365941" target="_blank" >https://hdl.handle.net/11104/0365941</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/adbc69" target="_blank" >10.3847/1538-4357/adbc69</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Comparison of coronal hole and quiet-Sun chromosphere using IRIS Mg II h and k observations of polar off-limb regions

Popis výsledku v původním jazyce

Solar quiet regions are divided into coronal hole regions (CH) and quiet-Sun regions (QS). The global magnetic field in CH is considered open to interplanetary space, while that in QS is closed. To constrain the solar atmosphere and solar wind model, we statistically compared CH and QS in the chromosphere by quantitatively analyzing all available high-resolution spectral data sets of polar off-limb regions taken from the entire catalog of the Interface Region Imaging Spectrograph (IRIS) satellite. We extracted the characteristic quantities from the Mg ii h and k line profiles and compared the dependence of those quantities on the height from the photospheric limb. The main findings are as follows. First, the integrated intensities in the Mg ii k line show a steeper decrease with height in QS while they remain bright at higher altitudes in CH. Second, the unsigned line-of-sight velocities in the Mg ii k line generally increase with height in both regions, although the unsigned velocities increase with height more strongly in QS than in CH. Third, the Mg ii k line widths increase just above the limb and then decrease with height in both CH and QS, but are overall larger for CH than for QS, especially at the lower altitudes. Finally, we found the ratio of the Mg ii k and h lines to show a two-step increase with height in both regions. The results suggest the spicules are higher in CH, and the CH chromosphere exhibits faster motions than the QS.

Název v anglickém jazyce

Comparison of coronal hole and quiet-Sun chromosphere using IRIS Mg II h and k observations of polar off-limb regions

Popis výsledku anglicky

Solar quiet regions are divided into coronal hole regions (CH) and quiet-Sun regions (QS). The global magnetic field in CH is considered open to interplanetary space, while that in QS is closed. To constrain the solar atmosphere and solar wind model, we statistically compared CH and QS in the chromosphere by quantitatively analyzing all available high-resolution spectral data sets of polar off-limb regions taken from the entire catalog of the Interface Region Imaging Spectrograph (IRIS) satellite. We extracted the characteristic quantities from the Mg ii h and k line profiles and compared the dependence of those quantities on the height from the photospheric limb. The main findings are as follows. First, the integrated intensities in the Mg ii k line show a steeper decrease with height in QS while they remain bright at higher altitudes in CH. Second, the unsigned line-of-sight velocities in the Mg ii k line generally increase with height in both regions, although the unsigned velocities increase with height more strongly in QS than in CH. Third, the Mg ii k line widths increase just above the limb and then decrease with height in both CH and QS, but are overall larger for CH than for QS, especially at the lower altitudes. Finally, we found the ratio of the Mg ii k and h lines to show a two-step increase with height in both regions. The results suggest the spicules are higher in CH, and the CH chromosphere exhibits faster motions than the QS.

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/GA25-18282S" target="_blank" >GA25-18282S: Kosmické koronografy ESA s českou účastí</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

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

1538-4357

Svazek periodika

983

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

17

Strana od-do

108

Kód UT WoS článku

001464716000001

EID výsledku v databázi Scopus

2-s2.0-105003045840