could be as small as $\sim$10 in the foreground and $\sim$10 in the background.

Finally, we note that many Galactic field stars will each produce $<3$ photons in the CCCP image, too faint for detection as a point source. The undetected foreground stars produce a total of $\sim10,000$ X-ray photons in the soft ($0.5-2$ keV) band. These photons will appear as a uniform diffuse X-ray component in the CCCP image. These stars likely contribute $\sim$1% of the observed $> 10^6$ count soft X-ray emission that pervades the CCCP field [@Townsley11b].

Properties of Cluster Contaminants \[contamination\_properties\_section\]
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Basic properties of the simulated contaminating populations $-$ spatial distributions, X-ray median energies, and $J$-band magnitudes $-$ are described here. These properties are employed by @Broos11b to establish Carina membership probabilities for each of the CCCP sources.

Spatial Density and Distribution \[spatial\_contamination\_subsection\]
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Our simulations predict that roughly 5000 contaminants, or approximately 1 source arcmin$^{-2}$ in the 5112 arcmin$^2$ CCCP survey, will be detected in our CCCP observations. About half of these are expected to be extragalactic sources, and half Galactic field stars. With $>14000$ detected sources [@Broos11a], contaminants are expected to comprise $\sim35$% of the detected CCCP source population. For comparison, the source 