Panela: accretion rate evolution for a young high-mass protostar approximated from the RMHD simulations of Peters et al. (2011; dashed lines). Panel b: time evolution of the protostar’s mass derived from its accretion rate, Ṁ (t) (panel a, dashed line). Panel c: time evolution of the protostar’s total luminosity derived from its mass, M (t) (panel b, dashed line), using the Hosokawa & Omukai (2009) mass-luminosity relation (Fig. F.3). Inall panels the solid line shows the result obtained when keeping a constant accretion rate (10⁻⁴ M_⊙ yr⁻¹) after ~6 × 10⁴ yr.