Black hole mass spectrum as a function of the CO core mass from various authors. Solid blue line: this work, non-rotating progenitors at [Fe/H] =−3; long dashed orange line: set D of W17 (we note that these models are obtained from stellar tracks computed at Z = 0.1 Z_⊙ for which the mass loss has been inhibited, making these models distinct from those we used to compute the final remnant masses.); dashed pink line: models from Spera & Mapelli (2017) with Z = 1.3 × 10⁻² Z_⊙ (S17). Circles (crosses) represent the models that are stable (unstable) against pair production, and squares are the stars disrupted by PISNe.