3D distribution of O stars in our model (top) and radiation field density at the centre of the simulation box (bottom). Colours in the top panel represent the effective temperature of the stars. The yellow data points in the lower panel are from Sher (1965), blue stars show the data from De Buizer et al. (2024). The blue shaded band shows the uncertainty in the stars’ radiation component, while the gray dash-dotted line shows the Galactic ISRF model from Porter & Strong (2005).