DETECTION OF NONTHERMAL RADIO-EMISSION FROM CORONAL X-RAY JETS

We report the detection of a type III burst in association with a dyna mic X-ray coronal jet observed by Yohkoh/SXT. The type III burst obser ved with the Nancay (France) multifrequency radioheliograph is spatial ly and temporally coincident with the X-ray jet. The radio locations a t different frequencies (236.6 and 164 MHz) are aligned along the leng th of the jet. The observation of the type III burst in association wi th the X-ray jet implies the acceleration of electrons to several tens of keV, along with the heating responsible for the production of soft X-rays. This association implies the existence of open field lines in dense coronal structures identified on the Sun's disk. This is the fi rst observation of dense coronal structures on the disk, along which t ype III emitting nonthermal electrons propagate. We find that this str ucture begins to form before the type III emission. At the time of the type III burst we estimate a density of 6-10 x 10(8) cm(-3) for a tem perature of similar to 5-6 MK at an altitude of 20,000 km.