Non-Maxwellian Diagnostics from SDO/EVE Spectra of an X-class Flare

Figure 1: The X5.4 flare of 2012 March 07. Panels (a) and (b) show the GOES X-ray flux and its derivative, respectively. The vertical blue line shows the period selected as for obtaining the background EVE spectrum, while the red vertical line denotes the flare peak. Panels (c)-(e) show the evolution of the flare, as observed by the 94 Â channel of the Atmospheric Imaging Assembly (AIA) instrument onboard the SDO. From (Ref. [4]).

Figure 2: Results of the diagnostics of the kappa-distributions over the early and impulsive phase of the flare until the peak at 00:25 UT (left) and during the onset of the gradual phase starting from 00:25 UT (right). Observed line ratios are shown by diamonds together with the respective error-bars, while the theoretical ratios are plotted by full lines, where black stands for Maxwellian (kappa equal to infinity), green for kappa=5, orange for kappa=3, and red for kappa=2. Asterisks and triangles stand for the predicted ratios given the DEMs derived from a range of Fe X-XXIV lines. From (Ref. [4]).