Dean-Yi Chou et al. 2009 ApJ 706 909 doi:10.1088/0004-637X/706/1/909
Dean-Yi Chou1, Ming-Hsu Yang1, Hui Zhao1, Zhi-Chao Liang1 and Ming-Tsung Sun2
Show affiliationsObserved acoustic power in magnetic regions is lower than the quiet Sun because of absorption, emissivity reduction, and local suppression of solar acoustic waves in magnetic regions. In the previous studies, we have developed a method to measure the coefficients of absorption, emissivity reduction, and local suppression of sunspots. In this study, we go one step further to measure the spatial distributions of three coefficients in two active regions, NOAA 9055 and 9057. The maps of absorption, emissivity reduction, and local suppression coefficients correlate with the magnetic map, including plage regions, except the emissivity reduction coefficient of NOAA 9055 where the emissivity reduction coefficient is too weak and lost among the noise.
Sun: activity; Sun: helioseismology; Sun: interior; sunspots
Issue 1 (2009 November 20)
Received 2009 June 30, accepted for publication 2009 October 13
Published 2009 November 6
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