Shown in the right panel is the NTT +EFOSC2 one-dimensional spectrum obtained on 2016 April 4.3 UT and extracted without background subtraction (red), and with background subtraction (black) using three slightly different background regions, as indicated in the left panels. Each of the extracted spectra reveals a feature which if associated with Hα would imply a −v_abs = 1, 500 km s⁻¹.