GEPI

I will show the preliminary results of the Frontier Fields Lens Modeling Comparison Project. The Frontier Field Initiative is currently a major effort of the HST to provide ultra-deep observations of six strong lensing clusters. The goal of this survey is to combine the sensitivity of HST with the magnification power of these galaxy clusters to peer deeper into the Universe than ever before. These observations are revealing galaxies up to two orders of magnitude fainter than previously observed. In order to characterize the properties of these sources, a crucial step is the construction of robust and reliable mass models for the lensing clusters. Several groups are currently employing different techniques for building such models using hundreds of multiple image systems newly discovered in the HST images. To assess the performance of these methods so to improve their results, they have joined a common effort to test their mass models against simulated HST observations mimicking the quality of the Frontier Fields data. In this talk, I will show the results from the first two rounds of simulations and illustrate the plans for the near future.