A model for galaxy–galaxy strong lensing statistics in surveys

Abstract

Photometric wide-area observations in the next decade will be capable of detecting a large number of galaxy-scale strong gravitational lenses, increasing the gravitational lens sample size by orders of magnitude. To aid in forecasting and analysis of these surveys, we construct a flexible model based on observed distributions for the lens and source properties and test it on the results of past lens searches, including SL2S, SuGOHI and searches on the COSMOS HST and DES fields. We use this model to estimate the expected yields of some current and planned surveys, including Euclid Wide, Vera Rubin LSST, and Roman High Latitude Wide Area. The model proposed includes a set of free parameters to constrain on the identifiability of a lens in an image, allowing construction of prior probability distributions for different lens detection methods. The code used in this work is made publicly available.