Figure 2: Faint X-ray sources number counts in the 0.5–2 keV band and in four redshift ranges. Blue points are from X-ray detections at the position of ERS and GOODS-MUSIC galaxies ; green points are from Chandra-COSMOS ; red points are from XMM-COSMOS . Circles = sources, squares = sources, triangles = , and star = sources. Diamond = Treister et al. determination . The upper limit in the lower right panel is from Table 1. The thin solid curves are model number counts based on the best fit high- luminosity functions presented in .