Achieved [CII] (upper panel) and continuum (lower panel) rms sensitivities. The blue dots indicate the values measured in individual fields and the red squares the mean values in the two redshift windows. The red error bars on the plots are the standard deviation in each redshift range. The actual uncertainties on the mean values are indeed times smaller (central-limit theorem) and are smaller than the size of the squares. Since the [CII] sensitivities were measured using different bandwidths because of the different line widths, we normalized the measurements to a bandwidth of 235 km s⁻¹ by dividing our raw measurements by . The solid black lines indicate the trend of the [CII] flux I_[CII] and continuum flux S_{(1 + z)158 μm} versus frequency (and thus redshift) at constant [CII] luminosity L_[CII] and fixed infrared luminosity L_IR, respectively.