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The Solar granulation in different heights
Author(s) -
Balthasar H.
Publication year - 1998
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.2123190607
Subject(s) - photosphere , physics , spectral line , intensity (physics) , doppler effect , correlation coefficient , astrophysics , geodesy , geology , optics , astronomy , statistics , mathematics
Intensity images and Doppler‐velocity maps of the quiet sun in different heights are obtained from simultaneously recorded spectra of different lines. A relation between the intensity images is recognizable up to formation heights of 900 km above continuum, but the correlation coefficient changes sign above 400 km. The core of H α shows a different pattern without any correlation to the continuum layer. Extreme Doppler velocities as well as the rms‐velocities have minima at a height of 400 km, values of about 2 km/s occur in deep photospheric layers and 2.5 km/s in a height of 900 km. The velocities in the lower and in the upper photosphere are well correlated indicating that the pattern of the velocity field is preserved up to higher layers than the intensity pattern. H α ‐velocities reach values up to 10 km/s and more, they show no correlation with the continuum intensities and almost no with the line core intensities.