THE 09 SEPTEMBER 1989 GAMMA-RAY FLARE - MULTISITE PARTICLE-ACCELERATION AND SHOCK-EXCITED RADIO-EMISSION DURING QUASI-PERPENDICULAR AND QUASIPARALLEL PROPAGATION

This is a case study of the location of particle acceleration sites du ring an impulsive flare and its subsequent coronal shock which occurre d on 09 September 1989. Joint radio, hard X-ray/gamma-ray, and H alpha observations of the flare impulsive emissions reveal that electron an d ion acceleration results from successive energy release in different magnetic-structures. In this paper we attempt to identify these magne tic structures, during both the impulsive flare and the coronal shock propagation. This is done by tracing essential features identified in high time resolution radio spectral and hard X-ray/gamma-ray data in r adio images, and comparing the spatial information with sequences of H alpha images and a static figure of the coronal magnetic field lines derived by extrapolating photospheric field measurements. During the i mpulsive phase signatures of energy release are found in different cor onal height ranges which are magnetically connected with a small part of an underlying active region that is invaded by an expanding H alpha flare ribbon. The magnetic field configuration comprises two sites at heights between 2 . 10(4) and 8 . 10(4) km above the primary highly c onfined flare. These sites are characterized by coronal magnetic field line systems crossing at nearly right angle. This provides for potent ial sites of efficient energy release and particle acceleration withou t demanding for extreme twist. The subsequent shock wave, revealed by type II radio burst emission, is found to propagate over large distanc es (similar to 1 R.) through the corona and to accelerate electrons in regions where it propagates along and across the ambient magnetic fie ld.