Ring-diagram analysis of the structure of solar active regions

Basu, Sarbani ; Antia, H. M. ; Bogart, Richard S. (2004) Ring-diagram analysis of the structure of solar active regions Astrophysical Journal, 610 (2). pp. 1157-1168. ISSN 0004-637X

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Official URL: http://iopscience.iop.org/0004-637X/610/2/1157?fro...

Related URL: http://dx.doi.org/10.1086/421843

Abstract

We measure differences in structure between active and quiet regions of the Sun using the frequencies of high-degree modes determined from ring-diagram analyses. We find that both the speed of sound and the adiabatic index Γ1 differ in active regions as compared with quiet regions. In the immediate subsurface layers, the sound speed is lower in active regions, but below a depth of about 7 Mm the opposite is true. A comparison of sound-speed inversion results with those for Γ1 indicates that at least a part of the differences between active and quiet regions is likely to be due to the structural and thermal perturbations caused by magnetic fields in the active region.

Item Type:Article
Source:Copyright of this article belongs to American Astronomical Society.
ID Code:12389
Deposited On:10 Nov 2010 06:18
Last Modified:16 May 2016 21:44

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