Spectra around the four targeted auroral lines corrected by the fit line derived from the sidebands. The dark gray region is the central region, the light gray regions are the sidebands, and the orange line denotes the zero value. [O III] λ4363 is on the top left, [N II] λ5755 is on the top right, [O II] λλ7320, 7330 is at the bottom left, and [S II] λλ4068, 4076 is at the bottom right.