and 4.1), these data yield an X-ray luminosity threshold (0.3–3.0keV) for the weakest detected sources of $\ga 8\times10^{28}$ergs$^{-1}$ for NGC 2547 cluster members near the centre of the EPIC field of view.

Source Detection
----------------

Version 6.0 of the [*XMM-Newton*]{} Science Analysis System was used for the initial data reduction and source detection. Unfortunately, the data were affected by several periods of high background. Data from the three cameras were individually screened for high background periods and these time intervals were excluded from all subsequent analysis. Observation intervals were excluded where the total count rate (for single events of energy above 10keV) in the instruments exceed 0.35s$^{-1}$ and 1.0s$^{-1}$ for the MOS and pn detectors respectively. The remaining useful exposure times were 29.0ks and 29.4ks for the MOS1 and MOS2 cameras, but only 13.7ks for the pn camera, which is more sensitive to high background intervals.

Images were created using the [*evselect*]{} task and a spatial sampling of 2 arcseconds per pixel. The event lists were filtered to exclude anomalous pixel patterns and edge effects by including only those events with “pattern”$\leq 12$. The contrast between background and source events was also increased by retaining only those events with energies 