Fig. 9. Spatial distribution of Class III sources in the Ophiuchi Cloud. White dots show the position of Class III sources excluding the early-type star S1. Crosses show X-ray detected Class III sources (Montmerle et al. 1983; CMFA; Koyama et al. 1994; Kamata et al. 1997; this article). The dashed contour map is an estimate of the Class III source surface density (in arbitrary linear units) obtained using a sum of Gaussians (FWHM=8´) centered on each Class III source position. Plus signs show the positions of the density peaks of Class II sources (see Fig. 8). Class III sources with known spectral types are labeled, and put in an H-R diagram in Fig. 10.