Hard X-Rays Associated with Type III Radio Bursts

Abstract

During a period of 12 minutes on 2002 July 19 14:23-14:35 UT, the WAVES instrument on WIND observed six interplanetary type III radio bursts, one approximately every 2 minutes, and each was accompanied by a weak hard X-ray (HXR) burst (12-15 keV) observed by RHESSI. The radio bursts are observed up to 150 MHz with some up to 600 MHz. Simultaneous observations by TRACE show jetlike eruptions emanating from the region of HXR emission. The observed HXRs are inconsistent with emission from the escaping type III-producing nonthermal electrons. We suggest that the type III acceleration process may be associated with an explosive release of 5 × 1026 ergs in the form of a superhot (26 MK) thermal plasma in the corona, an energy comparable to that associated with the type III-producing electrons.