Spatial magneto-seismology : effect of density stratification on the first harmonic amplitude profile of transversal coronal loop oscillations
Verth, G., Van Doorsselaere, Tom, Erdélyi, R. (Robertus) and Goossens, Marcel. (2007) Spatial magneto-seismology : effect of density stratification on the first harmonic amplitude profile of transversal coronal loop oscillations. Astronomy & Astrophysics, Vol.475 (No.1). pp. 341-348. ISSN 0004-6361
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Official URL: http://dx.doi.org/10.1051/0004-6361:20078086
Context. The new generation of extreme-ultraviolet (EUV) imagers onboard missions such as the Solar Dynamics Observatory (SDO)and Solar Orbiter (SO) will provide the most accurate spatial measurements of post-flare coronal loop oscillations yet. The amplitude profiles of these loop oscillations contain important information about plasma fine structure in the corona.
Aims. We show that the position of the anti-nodes of the amplitude profile of the first harmonic of the standing fast kink wave of a coronal loop relate to the plasma density stratification of that loop.
Methods. The MHD kink transversal waves of coronal loops are modelled both numerically and analytically. The numerical model implements the implicit finite element code pollux. Dispersion relations are derived and solved analytically. The results of the two methods are compared and verified.
Results. Density stratification causes the anti-nodes of the first harmonic to shift towards the loop footpoints. The greater the density stratification, the larger the shift. The anti-node shift of the first harmonic of a semi-circular coronal loop with a density scale height
H = 50 Mm and loop half length L = 100 Mm is approximately 5.6Mm. Shifts in the Mm range are measureable quantities providing valuable information about the subresolution structure of coronal loops.
Conclusions. The measurement of the anti-node shift of the first harmonic of the standing fast kink wave of coronal loops is potentially a new tool in the field of solar magneto-seismology, providing a novel complementary method of probing plasma fine structure in the
|Item Type:||Journal Article|
|Subjects:||Q Science > QB Astronomy|
|Divisions:||Faculty of Science > Physics|
|Library of Congress Subject Headings (LCSH):||Sun -- Loop prominences, Sun -- Corona -- Magnetic fields, Solar oscillations|
|Journal or Publication Title:||Astronomy & Astrophysics|
|Official Date:||November 2007|
|Page Range:||pp. 341-348|
|Access rights to Published version:||Open Access|
|Funder:||National Science Foundation (U.S.) (NSF), Országos Tudományos Kutatási Alapprogramok (OTKA), Engineering and Physical Sciences Research Council (EPSRC)|
|Grant number:||TO43741 (OTKA)|
Abramowitz, M., & Stegun, I. A. 1965, Handbook of Mathematical Functions,
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