Intensity distribution for the subsequent simulations derived from denoising a ROSAT PSPC observation of the Puppis A SNR. This distribution has a uniform background with the "signal" scaled such that its peak intensity is equal to the background level (e.g., the peak intensity for the total data will be twice the background level). Simulated data are obtained by scaling this distribution to get the mean pixel counts and generating Poisson random numbers from these means.