Line width (top) and central velocity relative to the source velocity (bottom) of the spectrally unresolved CO rovibrational absorption spectra (﹩v=0\to 2﹩) for IRAS 03445+3242. The line widths are not deconvolved and thus are influenced by an instrumental velocity resolution of 7.5 km s⁻¹ (presented as horizontal dotted lines in the right top panel). The red and blue squares represent the line widths (top) and the central velocities (bottom) of R- and P-branch transitions, respectively. The vertical bars indicate the 1σ error, which does not take into account the uncertainty in the wavelength calibration (<∼1 km s⁻¹).