Origin of Line Broadening in Fading Granules: Influence of Small-scale Turbulence

Autor: Ryohtaroh T. Ishikawa, Yukio Katsukawa
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: The Astrophysical Journal, Vol 975, Iss 1, p 98 (2024)
Druh dokumentu: article
ISSN: 1538-4357
DOI: 10.3847/1538-4357/ad71cd
Popis: In the quiet region of the solar photosphere, turbulent convective motions of the granular flows naturally drive the subgranular-scale flows. However, evaluating such small-scale velocities is challenging because of the limited instrumental resolution. Our previous study, R. T. Ishikawa et al., found line-broadening events during the fading process of granules; however, their physical mechanism has remained unclear. In the present study, we observed the fading granules with the Hinode-SOT/SP and performed spectral line inversions. Moreover, we investigated the broadening events of synthesized spectra in fading granules reproduced by the MURaM simulation. Our results demonstrated that the small-scale turbulent motions are excited in the fading process, and such turbulent flows contribute to line broadening. The spectral line widths can be potential tracers of the photospheric turbulent flows.
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