The first high spectral resolution and white–light images obtained at the THEMIS telescope with the Italian Panoramic Monochromator (IPM), are analyzed to study in- tensity and velocity fluctuations in the photosphere of the sun. Monochromatic images, in two spectral ranges around 538.03 nm (C I line) and 557.61 nm (Fe I line), are used to char- acterize the vertical structure of the photosphere. Granulation cells and granules are obtained by segmentation of white-light images using suitable finding algorithms. We observe the height dependence of velocity vs. inten- sity fluctuations, and we found a dependence of velocity and intensity on granule dimension. Our results show that granules increase their intensity with dimension in the lower solar photo- sphere. In the higher photosphere, on the contrary, the intensity decreases with the dimension.

Dependence of the photospheric vertical flow characteristics on the granule dimension

CARBONE, Vincenzo;
1999

Abstract

The first high spectral resolution and white–light images obtained at the THEMIS telescope with the Italian Panoramic Monochromator (IPM), are analyzed to study in- tensity and velocity fluctuations in the photosphere of the sun. Monochromatic images, in two spectral ranges around 538.03 nm (C I line) and 557.61 nm (Fe I line), are used to char- acterize the vertical structure of the photosphere. Granulation cells and granules are obtained by segmentation of white-light images using suitable finding algorithms. We observe the height dependence of velocity vs. inten- sity fluctuations, and we found a dependence of velocity and intensity on granule dimension. Our results show that granules increase their intensity with dimension in the lower solar photo- sphere. In the higher photosphere, on the contrary, the intensity decreases with the dimension.
Sun: photosphere ; Sun: granulation ; techniques: image processing
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/20.500.11770/149705
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