J/ (J − H) CMD for the stars in the CrW region. The isochrone of 2 Myr (Z = 0.02) by Marigo et al. (2008) and PMS isochrones of age 0.1, 1, 2, 5 and 10 Myr taken from Siess et al. (2000) corrected for a distance of 2.9 kpc and a reddening E(B − V)_min = 0.25 are also shown. The symbols are the same as in Fig. 9 (see Sect. 4.3.1 for the classification scheme). The shown masses and spectral types have been taken from the 1 Myr PMS isochrone of Siess et al. (2000).