Detalles de publicación
PP 015105
On the Source of Propagating Slow Magneto-acousticWaves in Sunspots
(1) Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast, BT7 1NN, UK;
(2) Department of Physics and Astronomy, California State University Northridge, Northridge, CA, 91330, U.S.A;
(3) Instituto de Astrofisica de Canarias, 38205 La Laguna, Tenerife, Spain.
Recent high-resolution observations of sunspot oscillations using simultaneously
operated ground- and space-based telescopes reveal the intrinsic connection between different layers of the solar atmosphere. However, it is not clear whether these oscillations are externally driven or generated in-situ. We address this question by using observations of propagating slow magneto-acoustic waves along a coronal fan loop system. The observed wave amplitudes are found to be modulated with time, in addition to the generally observed decrease in oscillation amplitude with distance. Similar variations are observed all along the propagation path of the wave train. Employing multi-wavelength and multi-instrument data we study the amplitude variations with time as the waves propagate through different layers of the solar atmosphere. By comparing the amplitude-modulation period in different layers, we find that slow magneto-acoustic waves observed in sunspots are externally driven by photospheric p-modes, which propagate upwards into the corona before becoming dissipated.
operated ground- and space-based telescopes reveal the intrinsic connection between different layers of the solar atmosphere. However, it is not clear whether these oscillations are externally driven or generated in-situ. We address this question by using observations of propagating slow magneto-acoustic waves along a coronal fan loop system. The observed wave amplitudes are found to be modulated with time, in addition to the generally observed decrease in oscillation amplitude with distance. Similar variations are observed all along the propagation path of the wave train. Employing multi-wavelength and multi-instrument data we study the amplitude variations with time as the waves propagate through different layers of the solar atmosphere. By comparing the amplitude-modulation period in different layers, we find that slow magneto-acoustic waves observed in sunspots are externally driven by photospheric p-modes, which propagate upwards into the corona before becoming dissipated.