The three different continuum subtracted spectra in the region around 63 μm for TWA 04B. An arbitrary vertical shift was applied to the spectra for easy comparison. The vertical red line shows the rest wavelength of the [OI] 63.18 μm emission line. The green dashed area shows the position of a region where the noise dominates the emission. The red dashed horizontal lines show the the 3σ limit for the three spectra. The blue dashed horizontal lines show the 3σ limit when points inside the green dashed area are excluded.