Survey2Survey: A deep learning generative model approach for cross-survey image mapping

During the last decade, there has been an explosive growth in survey data and deep learning techniques, both of which have enabled great advances for astronomy. The amount of data from various surveys from multiple epochs with a wide range of wavelengths and vast sky coverage, albeit with varying brightness and quality, is overwhelming, and leveraging information from overlapping observations from different surveys has limitless potential in understanding galaxy formation and evolution. Synthetic galaxy image generation using physical models has been an important tool for survey data analysis, while using deep learning generative models shows great promise. In this paper, we present a novel approach for robustly expanding and improving survey data through cross-survey feature translation. We trained two types of generative neural networks to map images from the Sloan Digital Sky Survey (SDSS) into corresponding images from the Dark Energy Survey (DES), increasing the brightness and S/N of the fainter, lower quality source images without losing important morphological information. We demonstrate the robustness of our method by generating DES representations of SDSS images from outside the overlapping region, showing that the brightness and quality are improved even when the source images are of lower quality than the training images. Finally, we highlight several images in which the reconstruction process appears to have removed large artifacts from SDSS images. While only an initial application, our method shows promise as a method for robustly expanding and improving the quality of optical survey data and provides a potential avenue for cross-band reconstruction.