Verwichte, E. (Erwin), Foullon, C. (Claire) and Nakariakov, Valery M.. (2006) Fast magnetoacoustic waves in curved coronal loops. I, Trapped and leaky modes. Astronomy & Astrophysics, Vol.446 (No.3). pp. 1139-1149. ISSN 0004-6361

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Abstract

A study of vertically polarised fast magnetoacoustic waves in a curved coronal loop is presented. The loop is modeled as a semi-circular magnetic slab in the zero plasma-β limit. The governing equations for linear waves are derived. We show that the wave mode behaviour depends on the slope of the equilibrium density profile, which is modeled as a piece-wise continuous power law curve of index α. For all profiles, except for α = −4, wave modes are not trapped in the loop and leak out into the external medium through wave tunneling. The particular case of α = −4, which corresponds to a linearly increasing Alfvén speed profile, is examined in more detail as this is the only model that can support trapped wave modes. We compare the results with a straight slab model and find similar behaviour. Coupling between sausage and kink wave modes has not been found in the model.

Item Type:	Journal Article
Subjects:	Q Science > QB Astronomy
Divisions:	Faculty of Science > Physics
Library of Congress Subject Headings (LCSH):	Magnetohydrodynamics, Sun -- Loop prominences, Sun -- Corona, Solar oscillations
Journal or Publication Title:	Astronomy & Astrophysics
Publisher:	EDP Sciences
ISSN:	0004-6361
Date:	February 2006
Volume:	Vol.446
Number:	No.3
Page Range:	pp. 1139-1149
Identification Number:	10.1051/0004-6361:20053955
Status:	Peer Reviewed
Access rights to Published version:	Open Access
Funder:	Royal Society (Great Britain), Leverhulme Trust (LT), Particle Physics and Astronomy Research Council (Great Britain) (PPARC)
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URI:	http://wrap.warwick.ac.uk/id/eprint/3571

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