Periodic spectral line asymmetries in solar coronal structures from slow magnetoacoustic waves
Verwichte, E. (Erwin), Marsh, M., Foullon, C. (Claire), Van Doorsselaere, Tom, Moortel, Ineke de, Hood, Alan W. and Nakariakov, V. M. (Valery M.). (2010) Periodic spectral line asymmetries in solar coronal structures from slow magnetoacoustic waves. The Astrophysical Journal. Letters, Vol.724 (No.2). L194-L198. ISSN 2041-8205Full text not available from this repository.
Official URL: http://dx.doi.org/10.1088/2041-8205/724/2/L194
Recent spectral observations of upward moving quasi-periodic intensity perturbations in solar coronal structures have shown evidence of periodic line asymmetries near their footpoints. These observations challenge the established interpretation of the intensity perturbations in terms of propagating slow magnetoacoustic waves. We show that slow waves inherently have a bias toward enhancement of emission in the blue wing of the emission line due to in-phase behavior of velocity and density perturbations. We demonstrate that slow waves cause line asymmetries when the emission line is averaged over an oscillation period or when a quasi-static plasma component in the line of sight is included. Therefore, we conclude that slow magnetoacoustic waves remain a valid explanation for the observed quasi-periodic intensity perturbations.
|Item Type:||Journal Article|
|Subjects:||Q Science > QB Astronomy
Q Science > QC Physics
|Divisions:||Faculty of Science > Physics|
|Library of Congress Subject Headings (LCSH):||Sun -- Corona, Magnetohydrodynamics, Magnetohydrodynamic waves, Solar oscillations, Spectral line formation|
|Journal or Publication Title:||The Astrophysical Journal. Letters|
|Publisher:||Institute of Physics Publishing, Inc.|
|Funder:||Engineering and Physical Sciences Research Council (EPSRC), Science and Technology Facilities Council (Great Britain) (STFC), Seventh Framework Programme (European Commission) (FP7)|
|Grant number:||ST/F002769/1 (STFC), 220555 (FP7)|
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