E-Print Archive

There are 4021 abstracts currently viewable.


Advanced Search
Main Page Add New E-Print Submitter
News Help/FAQ About Preferences
Manage Key Phrase
Frequency drifts of 3-min oscillations in microwave and EUV emission above sunspots View all abstracts by submitter

Robert Sych   Submitted: 2011-11-02 19:19

We analyse 3-min oscillations of microwave and EUV emission generated at different heights of a sunspot atmosphere, studying the amplitude and frequency modulation of the oscillations, and its relationship with the variation of the spatial structure of the oscillations. High-resolution data obtained with the Nobeyama Radioheliograph, TRACE and SDO/AIA are analysed with the use of the Pixelised Wavelet Filtering and wavelet skeleton techniques. 3-min oscillations in sunspots appear in the form of repetitive trains of the duration 8-20 min (13 min in average). The typical interval between the trains is 30-50 min. The oscillation trains are transient in frequency and power. We detected a repetitive frequency drifts of 3-min oscillations during the development of individual trains. Wavelet analysis shows three types of the frequency drift: positive, negative and fluctuations without drift. The start and end of the drifts coincide with the start time and end of the train. The comparative study of 3-min oscillations in the sequences of microwave and EUV images show the appearance of new sources of the oscillations in sunspots during the development of the trains. These structures can be interpreted as waveguides that channel upward propagating waves, responsible for 3-min oscillations. A possible explanation of the observed properties is the operation of two simultaneous factors: dispersive evolution of the upwardly-propagating wave pulses and the non-uniformity of the distribution of the oscillation power over the sunspot umbra with different wave sources corresponding to different magnetic flux tubes with different physical conditions and line-of-sight angles.

Authors: R. Sych, T. V. Zaqarashvili, V. M. Nakariakov, S.A. Anfinogentov, K.Shibasaki and Y. Yan
Projects: Nobeyama Radioheliograph,SDO-AIA,TRACE

Publication Status: A&A (in press), 2011
Last Modified: 2011-11-03 15:21
Go to main E-Print page  Thermal Properties of A Solar Coronal Cavity Observed with the X-ray Telescope on Hinode  Energy Release and Particle Acceleration in Flares: Summary and Future Prospects  Edit Entry  Download Preprint  Submitter's Homepage Delete Entry 

Go to main E-Print pageGo to main E-Print page.
Previous AbstractPrevious Abstract.
Next AbstractNext Abstract.
Download PreprintDownload Preprint.
Submitter's HomepageSubmitters Homepage.
Edit EntryEdit Entry.
View All Abstracts By SubmitterView all abstracts by submitter.
Delete AbstractDelete abstract.

Latest Entries
Three-dimensional reconstruction of CME-driven shock-streamer interaction from radio observations: a different take on the diagnostics of coronal magnetic fields
The soft X-ray spectrometer polarimeter SolpeX
Variable emission mechanism of a Type IV radio burst
Inference of magnetic field strength and density from damped transverse coronal waves
Frequency-Distance Structure of Solar Radio Sources Observed by LOFAR
The birth of a coronal mass ejection
Properties of slow magnetoacoustic oscillations of solar coronal loops by multi-instrumental observations
Persistent Quasi-Periodic Pulsations During a Large X-Class Solar Flare
Magnetic helicity and fluxes in an inhomogeneous α squared dynamo
Properties of the Diffuse Emission around Warm Loops in Solar Active Regions
Comparative Study of Microwave Polar Brightening, Coronal Holes, and Solar Wind Over the Solar Poles
3He-rich Solar Energetic Particles from Sunspot Jets
Relative magnetic field line helicity
Forbush decreases and Geomagnetic Storms during a Highly Disturbed Solar and Interplanetary Period, 4‐10 September 2017
Helical Twisting Number and Braiding Linkage Number of Solar Coronal Loops
Small-scale motions in solar filaments as the precursors of eruptions
Modeling of Heliospheric Modulation of Cosmic-Ray Positrons in a Very Quiet Heliosphere
Interpreting magnetic helicity flux in solar flux emergence
Transient Inverse-FIP Plasma Composition Evolution within a Confined Solar Flare
The Role of a Tiny Brightening in a Huge Geo-effective Solar Eruption Leading to the St Patrick's Day Storm

Related Pages
MSU Solar Physics.
Max Millennium Science Mail Archive.
Max Millennium Message of the Day Mail Archive.
Max Millennium Flare Catalog

Archive Maintainer
Alisdair Davey

© 2003 Solar Physics Group - Montana State University