Diagram log T_eff – log g. Solid lines are evolutionary tracks of the grid described in Sect. 3.3 (with the non-rotating birthline). Dashed lines are iso-velocities of 50, 100, 150 and 200 km s^-1 of these models (from right to left). Dots indicate observations of Herbig Ae/Be stars with measured vsini from Alecian et al. (2013). The symbol and its colour depends on the value of w = vsini4/π: red triangles are used for w < 50 km s^-1, orange diamonds for 50 km s^-1<w< 100 km s^-1, yellow squares for 100 km s^-1<w< 150 km s^-1, green pentagons for 150 km s^-1<w< 200 km s^-1 and blue stars for 200 km s^-1<w< 250 km s^-1. A mean error bar is displayed, which corresponds to the averaged error over the stars for which an error is given.