Abundance ratios of [Si/O] versus [C/O]. The background coloured map with contours illustrates the metal yields from different stellar explosions coloured as follows: red region: Pop III Pair-instability Supernovae (PISN); green: Pop III Hypernovae; blue: Pop III Core-collapse Supernovae; grey and purple: Pop II Supernovae. Yields from the different stellar populations are scaled assuming a Salpeter IMF. The magenta circles illustrate that the NIRSpec absorption systems listed in Table 10 have values of [Si/O] similar to Pop III models, although some overlap with the yields of a single 15 M_⊙ Pop II star. Other intervening absorption-line systems at 4.5 < z_abs < 6 (Becker et al. 2019; Cooper et al. 2019; orange circles) fall in the same region of the abundance pattern space, whereas the grey circles representing very metal-poor damped Lyα absorbers at z_abs ∼ 3 (Cooke et al. 2011, 2017; Welsh et al. 2019) are also consistent with enrichment of Pop II core collapse SNe (Kobayashi et al. 2006; Nomoto et al. 2013; Limongi & Chieffi 2018, annotated as K06, N13, and L18).