Connecting solar flare hard X-ray spectra to in situ electron spectra

Aims. We aim to constrain the acceleration, injection, and transport processes of flare-accelerated energetic electrons by comparing their characteristics at Sun with those injected into interplanetary space. Methods. have identified 17 electron events well-observed SEPT instrument aboard STEREO which show a clear association hard X-ray (HXR) flare observed RHESSI spacecraft. compare spectral indices HXR spectra electrons. Because frequent double-power-law shape in situ spectra, we paid special attention choice index used for comparison. Results. The time difference between onsets associated type III microwave bursts suggests that are detected 1 AU apparent delays ranging from 9 41 min. While parent solar activity is clearly impulsive, also showing high correlation extreme ultraviolet jets, most studied occur temporal coincidence coronal mass ejections (CMEs). In spite onset presence CMEs low corona, find significant about 0.8 correlations increase if only anisotropy considered. This effects can alter leading strongly reduced imprint acceleration. Conclusions. conclude must be taken account when inferring initial acceleration events. Although our results suggest analyzed event sample, secondary might present could delays. However, limited variable pitch-angle coverage reason