Oral Presentation

CHITAH: Strong-Gravitational-Lens Hunter in Imaging Surveys

James H.H. Chan, Sherry Suyu, Tzihong Chiueh, Anupreeta More

Strong gravitationally lensed quasars provide powerful means to study galaxy evolution and cosmology. Current and upcoming imaging surveys will contain thousands of new lensed quasars, augmenting the existing sample by at least two orders of magnitudes. To find such lens systems, we built a robot, Chitah, that hunts for lensed quasars by modeling the configuration of the multiple quasar images. Specifically, given an image of an object that might be a lensed quasar, Chitah first disentangles the light from the supposed lens galaxy and the light from the multiple quasar images based on color information. A simple rule is designed to categorize the given object into a potential four-image or double-image lensed quasar system. The configuration of the identified quasar images is subsequently modeled to classify whether the object is a lensed quasar system. Our preliminary tests of Chitah using simulated lens systems and a real lens system show that this is a promising approach.