Detection of point sources in X-ray astronomical images using elliptical Gaussian filters

Since most energetic celestial sources in the Universe often exhibit a point-like appearance in the observed images, design of methods to detect and extract them is a hot research topic. An approach to detect and extract point sources in X-ray astronomical images that uses Gaussian smooth filters is proposed. As there might be false detections, a spurious source removal approach taking advantage of local background estimation and SNR thresholding is also proposed. We applied the new approach to the practical X-ray astronomical image of NGC 4552 (M89), and our approach achieves very good performance with a lower detection error rate of 5% compared to wavdetect and celldetect, and the speed of our approach is also comparable. We conclude that our approach is accurate, robust and efficient.