21 cm maps and spectra of eLARS04. The field of view has been adapted to show the full extent of the main SoFIA 2 detection. Top left: DECaLS optical composite image with HI column density contours at level 1.0 × 2ⁿ × 10¹⁹ cm⁻², with n = 0, 1, 2, …, 5 overlaid. The blue solid line shows the regions with S/N > 3. Contours fully included in the S/N ≥ 3 mask are shown in white, low signal-to-noise contours are shown in gray. A gray cross indicates the position of the galaxy according to optical coordinates, a synthesized beam shaped aperture centred on these coordinates was used to extract HI properties in the center. Top right: Column density map with the same contours as on the previous panel overlaid. Middle left: Moment-1 map. Middle right: Linewidth map. Bottom: Total 21 cm spectrum (gray) and beam-extracted 21 cm spectrum (black). Velocity centroids are indicated by a vertical solid line, and velocity at half width on either side of the peaks by dashed lines, in either gray or black for the total or beam extraction respectively.