HR: 16:45h
AN: SH42E-04 INVITED     [PDF]
TI: Solar Hard X-ray Bursts and Type III Radio Bursts
AU: * Lin, R P
EM: rlin@ssl.berkeley.edu
AF: Physics Dept and Space Sciences Laboratory, University of California, Berkeley., University of California, Space Sciences Laboratory, Berkeley, CA 94720-7450 United States
AB: Observations of solar type III radio bursts provided the first evidence for accelerated electrons of a few to a few tens of keV energy escaping the Sun. These escaping electrons have been detected in situ by spacecraft in the interplanetary medium (IPM) near 1 AU. Near the Sun, the electrons must produce hard X-rays (HXRs) through bremsstrahlung collisions with the relatively dense corona. In the past, HXR bursts (usually associated with a solar flare) were sometimes detected in close temporal coincidence with type III radio burst, but most type III bursts were unaccompanied by HXR bursts and vice versa. The Ramaty High Energy Solar Spectroscopic Imager (RHESSI) mission launched Feb. 2002 provides uniquely high sensitivity imaging and spectroscopy of HXRs down to 3 keV. RHESSI observations suggest that type III bursts are a phenomenon separate from flares, although often closely associated. The HXR emission from type III bursts alone has been detected for the first time, providing quantitative numbers and spectra for the radio-emitting electrons. The HXR imaging, together with radio and in situ electron observations from the Wind spacecraft, allow unambiguous tracing of the magnetic connection of the IPM back to the Sun, and also allow the physics of the escape, propagation, and radio emission processes to be studied in detail.
DE: 2118 Energetic particles, solar
DE: 7534 Radio emissions
DE: 7554 X rays, gamma rays, and neutrinos
DE: 7847 Radiation processes
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting