SH31A-2388
The Spectrum of Solar Wind Superhalo Electrons
Wednesday, 16 December 2015
Poster Hall (Moscone South)
Linghua Wang1, Liu Yang1, Chuan-Yi Tu2, Jiansen He2, Peter H Yoon3, R F Wimmer-Schweingruber4, Chadi S Salem5 and Stuart D Bale5, (1)Peking University, Institute of Space Physics and Applied Technology, Beijing, China, (2)Peking University, Beijing, China, (3)University of Maryland College Park, College Park, MD, United States, (4)University of Kiel, Kiel, Germany, (5)University of California Berkeley, Berkeley, CA, United States
Abstract:
The WIND/3DP measurements show that solar wind superhalo electrons are continuously present at energies above 2 keV in the interplanetary medium (IPM), even in absence of any significant solar and interplanetary activity (e.g., solar flares, shocks, etc.). The observed omnidirectional differential flux of quiet-time superhalo electrons generally fits to a power-law spectrum, J~E-β, with an average index β of ~2.4. Thus, superhalo electrons appear to be one of the most common electron acceleration phenomena in the heliosphere. The superhalo power-law spectrum shows no obvious correlation with sunspot number and solar wind core populations. If they are formed by acceleration through the IPM, then solar wind halo/strahl electrons can provide seed electrons for such acceleration. Finally, we will also present the correlation between the power-law spectrum of superhalo electrons and the kappa distribution of halo/strahl electrons.
