Observational signatures of the interaction between acoustic waves and the solar magnetic canopy
Abstract
Aims:We show that the spatial distribution (and its variation with frequency) of the power spectra of the velocity and intensity signals, in and around solar active regions, is a manifestation of the interaction of acoustic waves at the magnetic canopy.
Methods: We analysed 6 h of simultaneous, full-disk, velocity and intensity images obtained using the MOTH instrument tuned in the Na D2 line at 589 nm and K D1 line at 770 nm, and full-disk velocity images from the SOHO/MDI experiment using the Ni line at 677 nm.
Results: We propose that more than one type of magneto-acoustic-gravity wave is required to explain the well-known phenomena of p-mode absorption and power halos.
- Publication:
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Astronomy and Astrophysics
- Pub Date:
- September 2007
- DOI:
- 10.1051/0004-6361:20077247
- Bibcode:
- 2007A&A...471..961M
- Keywords:
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- Sun: atmosphere;
- Sun: oscillations;
- Sun magnetic fields