Left panel: IR excess in the range 1.24 − 22 μm vs. estimated mass of the objects. The most massive objects (more massive than ∼7 M_⊙) barely show an IR excess. Right panel: IR excess in the range 1.24 − 22 μm vs. estimated age. Ages and effective temperatures are respectively colour coded in the legend. The symbols stand for the Hα line profiles: circles (double-peaked), triangles (single-peaked), stars (P-Cygni profile) and diamonds (no information). We note that although it is not necessarily a one-to-one correlation, lower ages correspond to higher masses.