Eruption process of the filament captured in a wide range of the Hα spectral line. The maps are Dopplergrams wherein the blueshifted (dark) and redshifted (bright) features of the erupting material have manifested. The black lines labeled S1 and S2 on the map at 05:37:47 UT represent the artificial slits, and the green curved dashed-line outlines the arc-shaped filament (∼ 1.8 × 10¹⁰ cm). The orange arched line at 05:41:42 UT depicts the filament footpoint separation (∼1.6 × 10¹⁰ cm). During the eruption a large amount of the filament material is blueshifted up to 4.0 Å from the line center, also blobs-like structures are further blueshifted over 6.25 Å (red arrows). The symbol ‘+’ at 05:44:50 UT indicates the region from which a strongly blueshifted spectral profile is obtained and shown in Fig. 1. The bottom panels show blueshifted and redshifted spectral profiles from the regions outlined with blue and red circle marks (upper panels), the black profiles are from a quiet region. The redshifted profile (red plot) is caused by downflows close to the filament footpoint (see the text). The background hatched rectangles highlight the wavelength range of the Dopplergrams presented in each column of the upper panels. An animation of this figure is available online.