Apparent motion of penumbral grains in a sunspot simulation

Result code in 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>

Result on the web

<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>

Result language

angličtina

Original language name

Apparent motion of penumbral grains in a sunspot simulation

Original language description

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.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

<a href="/en/project/GF23-07633K" target="_blank" >GF23-07633K: Unveiling the principles of solar magneto-convection</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

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

Name of the periodical

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Volume of the periodical

699

Issue of the periodical within the volume

July

Country of publishing house

FR - FRANCE

Number of pages

11

Pages from-to

A211

UT code for WoS article

001525746000006

EID of the result in the Scopus database

2-s2.0-105010626222