SOLARNET Conference: The Many Scales of the Magnetic Sun

Detection of the Evershed flow by the application of the SOM technique

9 May 2023, 12:15

15m

Haus H, Telegrafenberg

Virtual Presentation 2) Small and large-scale magnetic features – from bright points to sunspots (Observations and Theory) Small and large-scale magnetic features – from bright points to sunspots (Observations and Theory)

Speaker

Paolo Romano (INAF - Catania Astrophysical Observatory)

Description

We present the results obtained from applying the Self Organizing Map technique to a spectral dataset of monochromatic images acquired by the Interferometric Bidimensional Spectropolarimeter at the Dunn Solar Telescope, along the Ca II 854.2 nm and Hα 656.28 nm lines. This technique allowed us to segment the photospheric and chromospheric penumbra fine structure, revealing the presence of the Evershed flow in the chromosphere along the portions of the penumbral filaments near the umbra. In addition, the flow velocity as a function of distance from the spot center in the peripheral regions of the super-penumbra was consistent with the inverse-Evershed flow. These signatures, along with slight differences in the chromospheric plasma velocities measured along the two spectral lines, provided us with the opportunity to combine the Evershed and inverse-Evershed flows in the same context, in accordance with the uncombed model of the sunspot penumbra.