Position of CEERS galaxies selected at 1 < z < 3 in the BPT diagram (left) and in the [S II]-based optical diagnostic (right). Optical star-forming galaxies and AGN are represented with blue and red circles, respectively. To be identified as an AGN, a source must lie in the AGN region (within its 1σ uncertainty) in at least one of the two optical diagnostics. Cyan crosses are included to highlight hidden AGN, that is, optical star-forming but near-IR AGN, as explained in the text. The green dashed line is a relation representative of star-forming galaxies at z = 2.3, from Shapley et al. (2015). The violet and gray dashed lines are the classification criterion and the maximum starburst condition from Kauffmann et al. (2003) and Kewley et al. (2001), respectively.