Bibcode
DOI
Luna, M.; Terradas, J.; Oliver, R.; Ballester, J. L.
Bibliographical reference
The Astrophysical Journal, Volume 676, Issue 1, pp. 717-727.
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3
2008
Journal
Citations
49
Refereed citations
49
Description
We study transverse fast magnetohydrodynamic waves in a system of two
coronal loops modeled as smoothed, dense plasma cylinders in a uniform
magnetic field. The collective oscillatory properties of the system due
to the interaction between the individual loops are investigated from
two points of view. First, the frequency and spatial structure of the
normal modes are studied. The system supports four trapped normal modes
in which the loops move rigidly in the transverse direction. The
direction of the motions is either parallel or perpendicular to the
plane containing the axes of the loops. Two of these modes correspond to
oscillations of the loops in phase, while in the other two they move in
antiphase. Thus, these solutions are the generalization of the kink mode
of a single cylinder to the double cylinder case. Second, we analyze the
time-dependent problem of the excitation of the pair of tubes. We find
that depending on the shape and location of the initial disturbance,
different normal modes can be excited. The frequencies of normal modes
are accurately recovered from the numerical simulations. In some cases,
because of the simultaneous excitation of several eigenmodes, the system
shows beating.