Impact of LSST Observing Strategy on Dark Energy Science

The Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) observing strategy will have a significant impact on the level of science that can be achieved. Thinking specifically about dark energy science, we focus on the impacts of Milky Way dust extinction and demonstrate that ~25% of the LSST baseline main survey area would not meet the selection cuts needed to deliver on dark energy constraints. Since the precision of these science constraints is proportional to survey area, we propose a reconfiguration of the LSST baseline main survey footprint to avoid high dust extinction regions, thereby delivering ~25% more area usable for dark energy science (Lochner et al. 2018, arXiv:1812.00515). We also investigate the impact of survey uniformity on dark energy probes, including large-scale structure. While the LSST baseline cadence now employs translational dithers, highly uniform coverage is still needed to ensure that fake large-scale structure induced by non-uniform depth does not dominate our systematic error budget (Awan et al. 2016, ApJ, 829, 50).