Average profiles (except for the Mg ii 4481 line) calculated using several unblended lines: five Si iii lines, ten O ii lines, and four N ii lines. For comparison, we also present the average of ten He i lines. The emission feature on the red side of the N ii profile belongs to the O iii 5006.8 Å line. For each element, the upper spectrum presents the difference between the average profiles from both nights. The apparent features in these difference spectra are mostly due to the variation of the radial velocity from one night to the next.
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