Illustrating the first free parameter (θ₁ = α_IMF), the high-mass slope of the IMF. Showing the number of stars per mass interval. We use a Chabrier (2001, Table 1, IMF 3) functional form as in Eq. (1) with α_IMF = − 2.29 as . The two sigma variance (± 2σ_prior) of is shown (see Table 1). For comparison the Kroupa et al. (1993) and Salpeter (1955) IMF are depicted. The mass fraction of each IMF that explodes as core-collapse supernova (CC-SN) is written in the top right.