Temporal Correlation of Hard X-Rays and Meter/Decimeter Radio Structures in Solar Flares |
| |
| Authors: | Kaspar Arzner Arnold O Benz |
| |
| Institution: | (1) Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland;(2) Institute of Astronomy, ETH Zürich, CH-8092 Zurich, Switzerland |
| |
| Abstract: | We investigate the relative timing between hard X-ray (HXR) peaks and structures in metric and decimetric radio emissions
of solar flares using data from the RHESSI and Phoenix-2 instruments. The radio events under consideration are predominantly
classified as type III bursts, decimetric pulsations and patches. The RHESSI data are demodulated using special techniques
appropriate for a Phoenix-2 temporal resolution of 0.1 s. The absolute timing accuracy of the two instruments is found to
be about 170 ms, and much better on the average. It is found that type III radio groups often coincide with enhanced HXR emission,
but only a relatively small fraction (∼20%) of the groups show close correlation on time scales < 1 s. If structures correlate,
the HXRs precede the type III emissions in a majority of cases, and by 0.69 ± 0.19 s on the average. Reversed drift type III
bursts are also delayed, but high-frequency and harmonic emission is retarded less. The decimetric pulsations and patches
(DCIM) have a larger scatter of delays, but do not have a statistically significant sign or an average different from zero.
The time delay does not show a center-to-limb variation excluding simple propagation effects. The delay by scattering near
the source region is suggested to be the most efficient process on the average for delaying type III radio emission. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
