Time evolution of the number of the ionising photons for models with an initial mass of 100 M_⊙. Photons emitted in the Lyman, HeI and He II continua by a normally-evolving model (without rotation) and a chemically-homogeneously-evolving model (with an initial rotational velocity of 500 km s^-1) from our grid are plotted. For comparison, the number of photons emitted in the He II continuum by a chemically-homogeneously-evolving Pop III model from Yoon et al. (2012) with similar initial mass and initial rotational velocity (in units of the critical rotation, which refers to v_ini ~ 520 km s^-1) is plotted by the dotted-dashed line. Note that the He II flux of the Pop III model may, however, be overestimated by a factor of three (see text).