zebra-structure – Community of European Solar Radio Astronomers

Zebra Stripes with High Gyro-Harmonic Numbers by Jan Benacek and Marian Karlicky

2022-12-20 146 views

The solar radio zebra patterns, or zebras, provide detailed diagnostics of plasma density and magnetic field in the corona. The zebras appear in radiograms during Type IV solar radio bursts as a series of parallel stripes that are narrow in frequency. The main emission model of radio zebras relies on a double plasma resonance, a resonance between the plasma frequency, gyro-harmonic of the cyclotron frequency, and the frequency of unstable upper-hybrid (UH) […]

Characteristics of stripes-pattern radio-emission sources by Khaled Alielden

2022-10-18 112 views

Investigating the generation mechanism for the stripes-pattern radio spectra is important to understand the dynamics of non-thermal electrons in several astronomical objects, including the Sun, Jupiter, and the Crab Pulsar. A new analytical study is carried out to identify the plasma characteristics of fiber- and zebra-pattern emission sources without an underlying density or magnetic model. The study suggests that the plasma condition of the source region for zebra pattern emission […]

PIC Simulation of Double Plasma Resonance and Zebra Pattern of Solar Radio Bursts
by Li et al.*

2021-05-25 138 views

Zebra patterns (ZPs) represent a spectral fine structure with equidistant or almost-equidistant stripes of enhanced intensity against a broadband emission background, frequently observed in the dynamic spectra of solar radio bursts such as type IVs. There exist many scenarios for ZPs. The most-accepted one is the model of double plasma resonance (DPR) which, as its name indicates, means simultaneous actions of two kinds of resonance instabilities, i.e., the cyclotron resonance […]

Density and magnetic field turbulence in solar flares estimated from radio zebra observations
by M. Karlicky and L. Yasnov

2020-07-14 177 views

Solar flares are characterized by fast plasma flows. In such plasma flows owing to the Kelvin-Helmholtz instability the maqnetohydrodynamic turbulence can be generated. Although, the turbulence plays an important role in solar flares, e.g., in acceleration of particles, a knowledge about the level of this turbulence is still very limited. In the present study we estimate the levels of this turbulence. For this purpose we use observations of the so called zebra […]

Alternative zebra-structure models in solar radio emission
by Chernov G.P.

2018-10-02 271 views

There is ongoing discussion in the literature about the nature of zebra-structure (ZS) in type IV radio bursts (Chernov, 2011). We showed the possibility of a model with whistler waves to explain many thin components of ZS stripes, taking into account the effects of scattering of the whistlers on fast particles. Here, we show some complex examples of observations of ZS bursts in different wave ranges, which are difficult to […]

Comparison of alternative zebra-structure models in solar radio emission
by G.P. Chernov et al.*

2017-05-16 505 views

Discussion about the nature of zebra-structure (ZS) in type IV radio bursts continues, despite the ten proposed models. First of all, this is due to the wide variety of stripes in each new phenomenon, making the explanation of all the fine details by any one mechanism becomes impossible. The most widespread explanation is the emission at different levels of double plasma resonance (DPR), sequential on the height surfaces in the magnetic […]