A Method Based on Wavelet Transforms for Source Detection in Photon-counting Detector Images. I. Theory and General Properties

摘要

We have developed a method based on wavelet transforms (WTs) to detect sources in astronomical images obtained with photon-counting detectors, such as X-ray images. The WT is a multiscale transform that is suitable for detection and analysis of interesting image features (sources) spanning a range of sizes. This property of the WT is particularly well suited to the case in which the point-spread function is strongly varying across the image, and it is also effective in the detection of extended sources. The method allows one to measure source count rates, sizes, and ellipticity, with their errors.