Observations of Solar Type II bursts at frequencies 10–30 MHz

Melnik, V.; Konovalenko, A. A.; Rücker, H. O.; Stanislavsky, A. A.; Abranin, E. P.; Lecacheux, A.; Mann, G.; Warmuth, A.; Зайцев, В. В.; Boudjada, M. Y.; Dorovskii, V.V.; Zaharenko, V. V.; Lisachenko, V. N.; Rosolen, C.

doi:10.1023/b:sola.0000036854.66380.a4

Cited by 37 publications

(44 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For example decameter type II bursts which have a fine structure in the form of type III-like bursts. The drift rates of these sub-bursts are close to the ordinary type III bursts velocity, but their duration is essentially lesser [34]. In this section we present the results when we inject the electron beam obliquely to the background magnetic field (θ = 45 • ) as in Section III.c.…”

Section: A Inhomogeneous Plasma Without An Electron Beammentioning

confidence: 88%

An alternative to the plasma emission model: Particle-in-cell, self-consistent electromagnetic wave emission simulations of solar type III radio bursts

Tsiklauri

2011

Physics of Plasmas

View full text Add to dashboard Cite

High-resolution (sub-Debye length grid size and 10000 particle species per cell), 1.5D Particle-inCell, relativistic, fully electromagnetic simulations are used to model electromagnetic wave emission generation in the context of solar type III radio bursts. The model studies generation of electromagnetic waves by a super-thermal, hot beam of electrons injected into a plasma thread that contains uniform longitudinal magnetic field and a parabolic density gradient. In effect, a single magnetic line connecting Sun to earth is considered, for which five cases are studied. (i) We find that the physical system without a beam is stable and only low amplitude level electromagnetic drift waves (noise) are excited. (ii) The beam injection direction is controlled by setting either longitudinal or oblique electron initial drift speed, i.e. by setting the beam pitch angle (the angle between the beam velocity vector and the direction of background magnetic field). In the case of zero pitch angle i.e. when v b · E ⊥ = 0, the beam excites only electrostatic, standing waves, oscillating at local plasma frequency, in the beam injection spatial location, and only low level electromagnetic drift wave noise is also generated. (iii) In the case of oblique beam pitch angles, i.e. when v b · E ⊥ = 0, again electrostatic waves with same properties are excited. However, now the beam also generates the electromagnetic waves with the properties commensurate to type III radio bursts. The latter is evidenced by the wavelet analysis of transverse electric field component, which shows that as the beam moves to the regions of lower density and hence lower plasma frequency, frequency of the electromagnetic waves drops accordingly. (iv) When the density gradient is removed, an electron beam with an oblique pitch angle still generates the electromagnetic radiation. However, in the latter case no frequency decrease is seen. (v) Since in most of the presented results the ratio of electron plasma and cyclotron frequencies is close to unity near the beam injection location, in order to prove that the generated by the non-zero pitch angle beam electromagnetic emission oscillates at the plasma frequency, we also consider a case when the magnetic field (and the cyclotron frequency) is ten times smaller. Within the limitations of the model, the study presents the first attempt to produce synthetic (simulated) dynamical spectrum of the type III radio bursts in the fully kinetic plasma model. The latter is based on 1.5D non-zero pitch angle (non-gyrotropic) electron beam, that is an alternative to the plasma emission classical mechanism for which two spatial dimensions are needed.

show abstract

Section: A Inhomogeneous Plasma Without An Electron Beammentioning

confidence: 88%

An alternative to the plasma emission model: Particle-in-cell, self-consistent electromagnetic wave emission simulations of solar type III radio bursts

Tsiklauri

2011

Physics of Plasmas

View full text Add to dashboard Cite

show abstract

“…Other bursts (type III bursts, type IIIb bursts, type III-like bursts, drift pairs, spikes, striae, type II and IV bursts) have durations from 1 s up to 1 hour and even more (Melnik et al, 2005(Melnik et al, , 2008a(Melnik et al, , 2008b. The profile of S-bursts is symmetrical ( Figure 5).…”

Section: Duration Of S-burstsmentioning

confidence: 95%

Solar S-bursts at Frequencies of 10 – 30 MHz

Melnik¹,

Konovalenko²,

Rücker³

et al. 2010

Sol Phys

Self Cite

View full text Add to dashboard Cite

Solar S-bursts observed by the radio telescope UTR-2 in the period 2001 -2002 are studied. The bursts chosen for a detailed analysis occurred in the periods 23 -26 May 2001, 13 -16 and 27 -39 July 2002 during three solar radio storms. More than 800 S-bursts were registered in these days. Properties of S-bursts are studied in the frequency band 10 -30 MHz. All bursts were always observed against a background of other solar radio activity such as type III and IIIb bursts, type III-like bursts, drift pairs and spikes. Moreover, Sbursts were observed during days when the active region was situated near the central meridian. Characteristic durations of S-bursts were about 0.35 and 0.4 -0.6 s for the May and July storms, respectively. For the first time, we found that the instantaneous frequency width of S-bursts increased with frequency linearly. The dependence of drift rates on frequency followed the McConnell dependence derived for higher frequencies. We propose a model of S-bursts based on the assumption that these bursts are generated due to the confluence of Langmuir waves with fast magnetosonic waves, whose phase and group velocities are equal.

show abstract

“…Type II bursts display a detailed fine structure (see e.g. Mel'nik et al 2004). The polarisation is similar to that of type III bursts (see below).…”

Section: Solar Radio Emissionmentioning

confidence: 99%

Aspects of the magnetosphere–stellar wind interaction of close-in extrasolar planets

Grießmeier¹

2007

Planetary and Space Science

View full text Add to dashboard Cite

show abstract

Observations of Solar Type II bursts at frequencies 10–30 MHz

Abstract: The results of the first observations of Type IV bursts at frequencies 10-30 MHz are presented. These observations were carried out at radio telescopes UTR-2 (Kharkov, Ukraine) and URAN-2 (Poltava, Ukraine) during the period

Cited by 37 publications

References 15 publications

An alternative to the plasma emission model: Particle-in-cell, self-consistent electromagnetic wave emission simulations of solar type III radio bursts

An alternative to the plasma emission model: Particle-in-cell, self-consistent electromagnetic wave emission simulations of solar type III radio bursts

Solar S-bursts at Frequencies of 10 – 30 MHz

Aspects of the magnetosphere–stellar wind interaction of close-in extrasolar planets

Contact Info

Product

Resources

About