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Author Fathalian, N. ♦ Safari, H.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword ASTROPHYSICS, COSMOLOGY AND ASTRONOMY ♦ DISPERSION RELATIONS ♦ MAGNETIC FIELDS ♦ MAGNETOHYDRODYNAMICS ♦ OSCILLATIONS ♦ PHOTOSPHERE ♦ S MATRIX ♦ SCALE HEIGHT ♦ SOLAR CORONA ♦ STRATIFICATION ♦ SUN ♦ ATMOSPHERES ♦ DIMENSIONS ♦ FLUID MECHANICS ♦ HEIGHT ♦ HYDRODYNAMICS ♦ MAIN SEQUENCE STARS ♦ MATRICES ♦ MECHANICS ♦ SOLAR ATMOSPHERE ♦ STARS ♦ STELLAR ATMOSPHERES ♦ STELLAR CORONAE
Abstract Collective transverse coronal loop oscillations seem to be detected in observational studies. In this regard, Luna et al. modeled the collective kink-like normal modes of several cylindrical loop systems using the T-matrix theory. This paper investigates the effects of longitudinal density stratification along the loop axis on the collective kink-like modes of the system of coronal loops. The coronal loop system is modeled as cylinders of parallel flux tubes, with two ends of each loop at the dense photosphere. The flux tubes are considered as uniform magnetic fields, with stratified density along the loop axis which changes discontinuously at the lateral surface of each cylinder. The MHD equations are reduced to solve a set of two coupled dispersion relations for frequencies and wavenumbers, in the presence of a stratification parameter. The fundamental and first overtone frequencies and longitudinal wavenumbers are computed. The previous results are verified for an unstratified coronal loop system. Finally, we conclude that an increased longitudinal density stratification parameter will result in an increase of the frequencies. The frequency ratios, first overtones to fundamentals, are very sensitive functions of the density scale height parameter. Therefore, stratification should be included in dynamics of coronal loop systems. For unstratified coronal loop systems, these ratios are the same as monoloop ones.
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 2010-11-20
Publisher Place United States
Journal Astrophysical Journal
Volume Number 724
Issue Number 1


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