Yung, L.Y. AaronSomerville, Rachel S.Dav´e, Romeel2023-03-152023-03-152023Yung, L. Y. A. et al. (2023). Semi-analytic forecasts for Roman – the beginning of a new era of deep-wide galaxy surveys. Monthly Notices of the Royal Astronomical Society, 519(1), 1578-1600. 10.1093/mnras/stac35951365-296610.1093/mnras/stac3595http://hdl.handle.net/10566/8583The Nancy Grace Roman Space Telescope, NASA’s next flagship observatory, will redefine deep-field galaxy survey with a field of view two orders of magnitude larger than Hubble and an angular resolution of matching quality. These future deep-wide galaxy surveys necessitate new simulations to forecast their scientific output and to optimise survey strategies. In this work, we present five realizations of 2-deg2 lightcones, containing a total of & 25 million simulated galaxies with −16 & MUV & −25 spanning z ∼ 0 to 10. This dataset enables a new set of experiments with the impacts of survey size on the derived galaxy formation and cosmological constraints. The intrinsic and observable galaxy properties are predicted using a well-established, physics-based semi-analytic modelling approach. We provide forecasts for number density, cosmic SFR, field-to-field variance, and angular two-point correlation functions, and demonstrate how the future wide-field surveys will be able to improve these measurements relative to current generation surveys. We also present a comparison between these lightcones and others that have been constructed with empirical models.enAstronomyPhysicsGalaxiesNASACosmologyArticle