Straight to the Source: Detecting Aggregate Objects in Astronomical Images with Proper Error Control.
The next generation of telescopes, coming on-line in the next decade, will acquire terabytes of image data each night. Collectively, these large images will contain billions of interesting objects, which astronomers callsources. One critical task for astronomers is to construct from the image data a detailedsource catalogthat gives the sky coordinates and other properties of all detected sources. The source catalog is the primary data product produced by most telescopes and serves as an important input for studies that build and test new astrophysical theories. To construct an accurate catalog, the sources must first be detected in the image. A variety of effective source detection algorithms exist in the astronomical literature, but few if any provide rigorous statistical control of error rates. A variety of multiple testing procedures exist in the statistical literature that can provide rigorous error control over pixelwise errors, but these do not provide control over errors at the level of sources, which is what astronomers need. In this paper, we propose a technique that is effective at source detection while providing rigorous control on source-wise error rates. We demonstrate our approach with data from the Chandra X-ray Observatory Satellite. Our method is competitive with existing astronomical methods, even finding two new sources that were missed by previous studies, while providing stronger performance guarantees and without requiring costly follow up studies that are commonly required with current techniques.
Battelle Memorial Institute, 505 King Ave., Columbus, OH 43214.
David A
DA
Friedenberg
Christopher R
CR
Genovese
Astrostatistics; Blind Source Detection; Multiple Testing