Magnetoacoustic waves in the narrowband dm-spikes sources

Karlický, M.; Jelínek, Petr; Mészárosová, H.

doi:10.1051/0004-6361/201016171

Cited by 22 publications

(15 citation statements)

References 34 publications

(32 reference statements)

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“…Development of that study revealed that, for the perturbations of the sausage symmetry, an important factor is also the broadness of the initial spectrum in comparison with the cut-off wavelength (Nakariakov et al 2005) and that in some cases the wavelet spectrum of the resulting wave train could be almost monochromatic. A&A 560, A97 (2013) Similar tadpole wavelet features were detected in a number of flare-associated radio bursts observed in the decimetric band (Mészárosová et al 2009a(Mészárosová et al ,b,a, 2011Karlický et al 2011;Mészárosová et al 2013). In particular, observations with the spatial resolution revealed the appearance of signals with the tadpole wavelet signatures in a fan structure above a coronal magnetic null point .…”

Section: Introductionmentioning

confidence: 91%

Fast magnetoacoustic wave trains in magnetic funnels of the solar corona

Pascoe

Nakariakov

Kupriyanova

2013

A&A

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Context. Fast magneto-acoustic waves are highly dispersive in waveguides, so they can generate quasi-periodic wave trains if a localised, impulsive driver is applied. Such wave trains have been observed in the solar corona and may be of use as a seismological tool since they depend upon the plasma structuring perpendicular to the direction of propagation. Aims. We extend existing models of magnetoacoustic waveguides to consider the effects of an expanding magnetic field. The funnel geometry employed includes a field-aligned density structure. Methods. We performed 2D numerical simulations of impulsively generated fast magneto-acoustic perturbations. The effects of the density contrast ratio, density stratification, and spectral profile of the driver upon the excited wave trains were investigated. Results. The density structure acts as a dispersive waveguide for fast magneto-acoustic waves and generates a quasi-periodic wave train similar to previous models. The funnel geometry leads to generating additional wave trains that propagate outside the density structure. These newly discovered wave trains are formed by the leakage of transverse perturbations, but they propagate upwards owing to the refraction caused by the magnetic funnel. Conclusions. The results of our funnel model may be applicable to wave trains observed propagating in the solar corona. They demonstrate similar properties to those found in our simulations.

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Section: Introductionmentioning

confidence: 91%

Fast magnetoacoustic wave trains in magnetic funnels of the solar corona

Pascoe

Nakariakov

Kupriyanova

2013

A&A

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“…Based on this, we proposed that the fiber bursts are generated by a modulation of the type IV radio emission by the magnetoacoustic wave trains. Karlický et al (2011) also found the wavelet tadpoles in sources of the narrowband dm-spikes.…”

Section: Introductionmentioning

confidence: 99%

Radio fiber bursts and fast magnetoacoustic wave trains

Karlický

Mészárosová

Jelínek

2013

A&A

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Aims. We present a model for dm-fiber bursts that is based on assuming fast sausage magnetoacoustic wave trains that propagate along a dense vertical filament or current sheet. Methods. Eight groups of dm-fiber bursts that were observed during solar flares were selected and analyzed by the wavelet analysis method. To model these fiber bursts we built a semi-empirical model. We also did magnetohydrodynamic simulations of a propagation of the magnetoacoustic wave train in a vertical and gravitationally stratified current sheet. Results. In the wavelet spectra of the fiber bursts computed at different radio frequencies we found the wavelet tadpoles, whose head maxima have the same frequency drift as the drift of fiber bursts. It indicates that the drift of these fiber bursts can be explained by the propagating fast sausage magnetoacoustic wave train. Using new semi-empirical and magnetohydrodynamic models with a simple radio emission model we generated the artificial radio spectra of the fiber bursts, which are similar to the observed ones.

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“…For the developed stage of the evolution the quasi-periodic wave trains are best described using wavelet analysis (Nakariakov et al 2004), which reveals the "crazy tadpole" characteristic signature also seen in data for propagating fast wave trains detected with the Solar Eclipse Coronal Imaging System (SECIS; Katsiyannis et al 2003;Cooper et al 2003) and in decimetric band radio bursts A&A 569, A12 (2014) (e.g. Mészárosová et al 2009aMészárosová et al ,b, 2011Mészárosová et al , 2013Karlický et al 2011Karlický et al , 2013. Recent numerical studies have extended models for dispersive evolution of impulsively generated wave trains to include current sheets .…”

Section: Introductionmentioning

confidence: 99%

Observation of a high-quality quasi-periodic rapidly propagating wave train using SDO/AIA

Nisticò

Pascoe

Nakariakov

2014

A&A

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Context. We present a new event of quasi-periodic wave trains observed in EUV wavebands that rapidly propagate away from an active region after a flare. Aims. We measured the parameters of a wave train observed on 7 December 2013 after an M1.2 flare, such as the phase speeds, periods and wavelengths, in relationship to the local coronal environment and the energy sources. Methods. We compared our observations with a numerical simulation of fast magnetoacoustic waves that undergo dispersive evolution and leakage in a coronal loop embedded in a potential magnetic field. Results. The wave train is observed to propagate as several arc-shaped intensity disturbances for almost half an hour, with a speed greater than 1000 km s −1 and a period of about 1 min. The wave train followed two different patterns of propagation, in accordance with the magnetic structure of the active region. The oscillatory signal is found to be of high-quality, i.e. there is a large number (10 or more) of subsequent wave fronts observed. The observations are found to be consistent with the numerical simulation of a fast wave train generated by a localised impulsive energy release. Conclusions. Transverse structuring in the corona can efficiently create and guide high-quality quasi-periodic propagating fast wave trains.

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Magnetoacoustic waves in the narrowband dm-spikes sources

Cited by 22 publications

References 34 publications

Fast magnetoacoustic wave trains in magnetic funnels of the solar corona

Fast magnetoacoustic wave trains in magnetic funnels of the solar corona

Radio fiber bursts and fast magnetoacoustic wave trains

Observation of a high-quality quasi-periodic rapidly propagating wave train using SDO/AIA

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