Institute for Advanced Study Informal Astrophysics Seminar

ABSTRACT: I will present some early results from 'the Tractor', a new approach for measuring astronomical sources in collections of images that David Hogg (NYU) and I have been developing. The idea to use generative (forward) modeling: we want to produce an astronomical source catalog that, along with image calibration information, allows us to predict the image pixels that were actually observed. If we have multiple images (in multiple bands, or from multiple instruments, say), we can optimize the source catalog to jointly best explain the observed images. Unlike traditional methods, we never have to co-add, degrade or reject any of the images, and by sampling we can capture the covariance in our measurements.