Multi-wavelength observations of the source region of Event no. 12. Panel a Depicts the filament channel as indicated by the yellow dashed line in AIA (Lemen et al. 2012) 304 Å image. The red dashed boundary line in panel b marks the PEA as observed in AIA 193 Å image. Panel c Illustrates the line-of-sight component of the HMI (Scherrer et al. 2012) magnetic field. The red dashed boundary and the yellow dashed line in (c) are the over-plotted PEA region and filament channel, respectively. The two ends of the reverse S-shaped filament channel are marked by the green circles and the underlying magnetic polarities are shown, which indicate a northward-pointing left-handed flux-rope.