LESIA - Observatoire de Paris

Non-Maxwellian distributions in the solar corona : Diagnostics for a transient coronal loop

lundi 7 décembre 2015, par Jaroslav Dudík (Academy of Sciences, République Tchèque)

Mercredi 16 décembre 2015 à 11h00 , Lieu : Salle de conférence du bâtiment 17

Observations of the solar wind show pervasive presence of the non-Maxwellian kappa-distributions of electron energies characterized by a power-law high-energy tail. Theory has shown that such distributions can arise in the solar corona during impulsive heating by magnetic reconnection and also wave-particle interactions. We explored the consequences of the presence of such kappa-distributions on the optically thin spectra of the solar corona emitted in the X-rays, UV, and visible wavelengths. In particular, several line combinations allow for diagnostics of the kappa-distributions. A diagnostic from the EUV line ratios observed by Hinode/EIS space-borne spectrometer is performed and it is shown that the electron distribution can be strongly non-Maxwellian.


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