scholarly journals On the Relative Position and Origin of Harmonics in the Spectra of Solar Radio Bursts of Spectral Types II And III

1962 ◽  
Vol 15 (2) ◽  
pp. 180 ◽  
Author(s):  
SF Smerd ◽  
JP Wild ◽  
KV Sheridan
Keyword(s):  
Solar Atmosphere ◽  
Relative Position ◽  
Solar Radio ◽  
Second Harmonic ◽  
Simple Theory ◽  
Radio Bursts ◽  
Type Ii ◽  
Solar Radio Bursts ◽  
Harmonic Emission ◽  
Type Iii

Observational results are given concerning the relative positions on the Sun's disk of the fundamental and second-harmonic emissions of solar radio bursts of spectral types II and III. Contrary to simple theory, the results indicate that it is common for the harmonic emission in type II bursts to arrive from directions corresponding to much lower heights in the solar atmosphere than the fundamental. The results for type III bursts are inconclusive but suggest the same trend.

scholarly journals Recent Results of Meter-decameter Wave Observations of Solar Flares

1989 ◽  
Vol 104 (2) ◽  
pp. 185-189
Author(s):  
N. Copalswamy ◽  
M. R. Kundu
Keyword(s):  
Solar Flares ◽  
Solar Radio ◽  
Radio Bursts ◽  
Type Ii ◽  
Solar Radio Bursts ◽  
Type Iii ◽  
Type Iv

AbstractWe present recent results from meter-decameter imaging of several classes of solar radio bursts: Preflare activity in the form of type III bursts, correlated type IIIs from distant sources, and type II and moving type IV bursts associated with flares and CMEs.

The Positions of Associated Type II and Type III Solar Radio Bursts

1974 ◽  
Vol 2 (5) ◽  
pp. 255-258 ◽  
Author(s):  
R. A. Duncan
Keyword(s):  
Solar Radio ◽  
Radio Bursts ◽  
Type Ii ◽  
Solar Radio Bursts ◽  
Type Iii ◽  
Intense Burst ◽  
Lower Frequencies

Large solar radio outbursts at metre wavelengths often consist of a group of type III bursts followed a few minutes later by a type II burst; in both spectral types the intense burst radiation drifts towards lower frequencies with time (Figure 1).

Theory of type II and type III solar radio bursts

1977 ◽  
Vol 20 (9) ◽  
pp. 951-965 ◽  
Author(s):  
V. V. Zaitsev
Keyword(s):  
Solar Radio ◽  
Radio Bursts ◽  
Type Ii ◽  
Solar Radio Bursts ◽  
Type Iii

Coherent Synchrotron Deceleration and the Emission of Type II and Type III Solar Radio Bursts

Nature ◽  
1969 ◽  
Vol 223 (5210) ◽  
pp. 1048-1049 ◽  
Author(s):  
A. F. KUCKES ◽  
R. N. SUDAN
Keyword(s):  
Solar Radio ◽  
Radio Bursts ◽  
Type Ii ◽  
Solar Radio Bursts ◽  
Type Iii

scholarly journals Solar Radio Bursts of Spectral Type II

1959 ◽  
Vol 12 (4) ◽  
pp. 327 ◽  
Author(s):  
JA Roberts
Keyword(s):  
Spectral Type ◽  
Solar Radio ◽  
Bone Structure ◽  
Second Harmonic ◽  
Radio Bursts ◽  
Type Ii ◽  
Harmonic Structure ◽  
Solar Radio Bursts ◽  
Band Splitting ◽  
Compound Type

The characteristics of bursts of spectral type II are studied in a sample of 65 bursts. Approximately half the bursts show harmonic structure and about half are compound type III-type II events. Band splitting, the doubling of both the fundamental and second harmonic bands, is also relatively common. A rather less common feature is the appearance of herring-bone structure in which the slowly drifting band of the type II burst appears to be a source from which rapidly drifting elements diverge towards lower and higher frequencies.

scholarly journals On the Theory of Type II and Type III Solar Radio Bursts. II. Alternative Model

1970 ◽  
Vol 23 (5) ◽  
pp. 885 ◽  
Author(s):  
DB Melrose
Keyword(s):  
Observational Data ◽  
Alternative Model ◽  
Solar Radio ◽  
Radio Bursts ◽  
Type Ii ◽  
Solar Radio Bursts ◽  
Fast Electrons ◽  
Type Iii ◽  
Stream Instability

It is argued that observational data on type III bursts point to the exciting agent for a burst being a bunch of fast electrons which experience no strong two� stream instability. Ways in which the two�stream instability might be suppressedare discussed.

scholarly journals Analysis of type II and type III solar radio bursts

2018 ◽  
Vol 1005 ◽  
pp. 012046 ◽  
Author(s):  
J.V Wijesekera ◽  
K.P.S.C Jayaratne ◽  
J. Adassuriya
Keyword(s):  
Solar Radio ◽  
Radio Bursts ◽  
Type Ii ◽  
Solar Radio Bursts ◽  
Type Iii

scholarly journals The Nature and Velocity of the Sources of Type II Solar Radio Bursts

1965 ◽  
Vol 18 (2) ◽  
pp. 167 ◽  
Author(s):  
The Late AA Weiss
Keyword(s):  
Magnetic Field ◽  
Speed Of Sound ◽  
Solar Radio ◽  
Frequency Drift ◽  
Radio Bursts ◽  
Type Ii ◽  
Solar Radio Bursts ◽  
Harmonic Emission ◽  
Band Splitting ◽  
Standard Density

Velocities of the sources of type II bursts are derived from rates of frequency drift using standard density models, both statistically for 21 bursts, and individually for 5 bursts extending over wide frequency ranges. The derived velocities exceed the speed of sound in the magnetic-field.free corona: on the average the velocity decreases with increasing height to a minimum of ,....., 750 kmjs at a little below I Ro' and j,hereafter slowly increases with height. The nature of the type II source is discussed in relation to these velocities, and also in relation to detailed measurements of harmonic ratios and band splitting for the five individual bursts. It is suggested that the type II source is either a strong parallel shock (direction of propagation of shock parallel to magnetic field) or a perpendicular shock. Magnetic field strengths of 2-20 G at 0�5 R 0 above the photosphere, decreasing to 1-10 G at 2 Ro, are derived. Finally, it is shown that theories by which fundamental emission arises in front of the shock, whilst harmonic emission originates in the interior of the shock, are untenable.

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