The Statistical Challenges of Wavelet-Based Source Detection

Wavelet functions are proving extremely useful for detecting sources in binned, two-dimensional photon counts images. In this chapter, we describe the mission-independent source detection algorithm WAAVDETEET, part of the Chandra Interactive Analysis of Observations (CIAO) software package, and discuss the statistical challenges we have faced in its development, such as: what is the best way to estimate the local background in each pixel, if it is a priori unknown? What is the best way to eliminate false detections caused by instrumental variations? And what is the significance of a detected source?