Solar energetic electron (left) and proton observations (right) of the 26 Dec 2013 SEP event. Each panel shows measurements at the two STEREO spacecraft and close to Earth at SOHO or ACE at comparable energy bins. Generally the energy increases from top to bottom. Intercalibration factors have been applied to the ACE/EPAM and SOHO/EPHIN electron measurements and to the EPHIN proton measurements following Lario et al. (2013). The shaded range marks the time when the second component sets in (see text).