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;
1999-01-01
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
