ISSN:
1573-093X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The hypothesis that solar impulsive bursts are comprised of quasi-quantised ultrarapid pulses convoluted with a variable pulse repetition rate R(t) is investigated by comparison of typical observations with numerical simulations. It is found that: (a) The ripple amplitude at burst peak increases rapidly with increase in the ratio Δ/T of pulse separation to pulse width. Consequently pulse widths T are generally much larger than the observed period Δt of small amplitude ripples. (b) In order to give a ripple amplitude of at least a few percent at burst peak together with reasonable burst rise and fall times without unreasonable ripple amplitude during rise and fall, the individual pulse shape must be sharply peaked but have substantial wings while the repetition rate R(t) must fall gradually away from its peak value but cut off rapidly in its wings. As a specific example, we present a simulation of the fast ripple structures observed in the impulsive 22 GHz burst of December 18, 1980. The relevance of these conclusions to physical modelling is briefly discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00165995
