A method to search for strong galaxy-galaxy lenses in optical imaging surveys

摘要

We present a semi-automated method to search for strong galaxy-galaxy lensesin optical imaging surveys. Our search technique constrains the shape ofstrongly lensed galaxies (or arcs) in a multi-parameter space, which includesthe third order (octopole) moments of objects. This method is applied to theDeep Lens Survey (DLS), a deep ground based weak lensing survey imaging to$R\sim26$. The parameter space of arcs in the DLS is simulated using realgalaxies extracted from deep HST fields in order to more accurately reproducethe properties of arcs. Arcs are detected in the DLS using a pixel thresholdingmethod and candidate arcs are selected within this multi-parameter space.Examples of strong galaxy-galaxy lens candidates discovered in the DLS F2 field(4 square degrees) are presented.