Long period oscillations of microwave emission of solar active regions: observations with NoRH and SSRT
Abstract
In this work we present the first results of study and comparison of the parameters of quasi-periodic long-term oscillations of microwave emission of large (>0.7 arcmin) sunspots as a result of simultaneous observations with two radioheliographs - NoRH (17 GHz) and Siberian Solar Radio Telescope (SSRT) (5.7 GHz) with 1 minute cadence. Radioheliographs have been working with quite large time overlap (about 5 hours) and have the high spatial resolution: 10 arcsec (NoRH) and 20 arcsec (SSRT). We have found that quasi-periodic long-term oscillations are surely observed at both frequencies with the periods in the range of 20-150 min. We detected common periods for common time of observations with two radioheliographs and interpret this as the consequence of the vertical-radial quasi-periodic displacements of sunspot as a whole structure.
- Publication:
-
Universal Heliophysical Processes
- Pub Date:
- March 2009
- DOI:
- Bibcode:
- 2009IAUS..257..155B
- Keywords:
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- high angular resolution;
- oscillations;
- magnetic fields;
- sunspots