Key points are not available for this paper at this time.
The C II 158 μ m line is one of the strongest IR emission lines, which has been shown to trace the star formation rate (SFR) of galaxies in the nearby Universe, and up to z ∼ 2. Whether this is also the case at higher redshift and in the early Universe remains debated. The ALPINE survey, which targeted 118 star-forming galaxies at 4.4 6 C II measurements (detections and upper limits) do not behave very differently to the z ∼ 4 − 6 data. We find a weak dependence of L (CII)/SFR on the Ly α equivalent width. Finally, we find that the ratio L (CII)/ L IR ∼ (1 − 3) × 10 −3 for the ALPINE sources, comparable to that of “normal” galaxies at lower redshift. Our analysis, which includes the largest sample (∼150 galaxies) of C II measurements at z > 4 available so far, suggests no or little evolution of the C II –SFR relation over the last 13 Gyr of cosmic time.
Schaerer et al. (Tue,) studied this question.