Schedule Oct 02, 2009
Relativistic Solar Electrons -- Where and How Are They Formed?
Ilan Roth (UC Berkeley)

Relativistic Solar Electrons are observed in conjunction with flares or coronal mass ejections (CMEs), however their formation mechanisms seem elusive. The existence of non-thermal electrons in the solar atmosphere and along the heliospheric field lines is deduced through emission of electromagnetic waves and via direct in situ satellite measurements at 1 AU. Their spectral shapes and the relative timing with respect to imaging and spectrographic observations may identify potential acceleration sites and processes controlling the formation of the (delayed with respect to a timing of a flare or initiation of CME) relativistic electrons. It is conjectured that the delayed acceleration occurs along the stretched, closed coronal field lines, when an anisotropic seed population of low-energy electrons is injected in conjunction with the high frequency coronal radio bursts behind the large CME, as recorded by radioheliographs. The energization proceeds due to resonant interaction with oblique whistler waves, which are excited by the nonisotropic seed electrons. The flare serves mainly as a time reference for the electromagnetic emissions, while the CME subsequently opens an access for the relativistic electrons to the interplanetary medium.

View poster as pdf.

Author entry (protected)