Next: X--ray Quiet PMS Up: Contents Previous: Fits to Evolutionary . The X--ray selected PMS candidates may not constitute a complete list. The primary factor is the sensitivity limit, complicated by the vignetting in the field of the PSPC which was used to make the source list. ... In order to better understand the completeness of the X--ray data, photometry of every star in both regions was undertaken. ... The X--ray quiet sources are distributed evenly across the field (see Figure 8 ). ...