Apparent motion of penumbral grains in a sunspot simulation

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F25%3A00637541" target="_blank" >RIV/67985815:_____/25:00637541 - isvavai.cz</a>

Výsledek na webu

<a href="https://hdl.handle.net/11104/0368562" target="_blank" >https://hdl.handle.net/11104/0368562</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202452474" target="_blank" >10.1051/0004-6361/202452474</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Apparent motion of penumbral grains in a sunspot simulation

Popis výsledku v původním jazyce

The bright heads of penumbral filaments, penumbral grains (PGs), are manifestations of hot plasma flows rising to the surface. They are observed to move horizontally towards the sunspot umbra or away from it. Recent analyses of observations indicate that the direction of this motion is related to the inclination of the surrounding magnetic field. Aims. The penumbra of a sunspot, simulated by the radiative magnetohydrodynamic code MURaM, is analysed to obtain typical physical conditions in PGs, compare them with those in the surroundings, describe their spatial distribution, and study their evolution. Methods. We used time series of images mapping intensity, temperature, magnetic field vector, and velocity vector in horizontal slices at the visible surface, in subsurface layers, and in vertical cuts through the simulation box to track PGs and compare, both statistically and in individual cases, the physical quantities inside them with those in the surroundings. Results. The statistical analysis of the simulation results provides average values of temperature, magnetic field strength and inclination, vertical velocity, and their changes with radial distance from the spot centre. We find a subtle difference between simulated PGs with opposite directions of motion when comparing the magnetic field inclinations inside and outside the PGs. The case studies, documented by movies, show that the differences in inclinations and the direction of motion may change during the lifetime of some PGs and that the turbulence in the surface layers introduces some randomness in the apparent motions of PGs.

Název v anglickém jazyce

Apparent motion of penumbral grains in a sunspot simulation

Popis výsledku anglicky

The bright heads of penumbral filaments, penumbral grains (PGs), are manifestations of hot plasma flows rising to the surface. They are observed to move horizontally towards the sunspot umbra or away from it. Recent analyses of observations indicate that the direction of this motion is related to the inclination of the surrounding magnetic field. Aims. The penumbra of a sunspot, simulated by the radiative magnetohydrodynamic code MURaM, is analysed to obtain typical physical conditions in PGs, compare them with those in the surroundings, describe their spatial distribution, and study their evolution. Methods. We used time series of images mapping intensity, temperature, magnetic field vector, and velocity vector in horizontal slices at the visible surface, in subsurface layers, and in vertical cuts through the simulation box to track PGs and compare, both statistically and in individual cases, the physical quantities inside them with those in the surroundings. Results. The statistical analysis of the simulation results provides average values of temperature, magnetic field strength and inclination, vertical velocity, and their changes with radial distance from the spot centre. We find a subtle difference between simulated PGs with opposite directions of motion when comparing the magnetic field inclinations inside and outside the PGs. The case studies, documented by movies, show that the differences in inclinations and the direction of motion may change during the lifetime of some PGs and that the turbulence in the surface layers introduces some randomness in the apparent motions of PGs.

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/GF23-07633K" target="_blank" >GF23-07633K: Odhalování principů konvekce v magnetických polích Slunce</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

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Svazek periodika

699

Číslo periodika v rámci svazku

July

Stát vydavatele periodika

FR - Francouzská republika

Počet stran výsledku

11

Strana od-do

A211

Kód UT WoS článku

001525746000006

EID výsledku v databázi Scopus

2-s2.0-105010626222