Optimizing the LSST Observing Strategy for Dark Energy Science: DESC Recommendations for the Wide-Fast-Deep Survey

Michelle Lochner; Daniel M. Scolnic; Humna Awan; Nicolas Regnault; Philippe Gris; Rachel Mandelbaum; Eric Gawiser; Husni Almoubayyed; Christian N. Setzer; Simon Huber; Melissa L. Graham; Renée Hložek; Rahul Biswas; Tim Eifler; Daniel Rothchild; Tarek Allam Jr; Jonathan Blazek; Chihway Chang; Thomas Collett; Ariel Goobar; Isobel M. Hook; Mike Jarvis; Saurabh W. Jha; Alex G. Kim; Phil Marshall; Jason D. McEwen; Marc Moniez; Jeffrey A. Newman; Hiranya V. Peiris; Tanja Petrushevska; Jason Rhodes; Ignacio Sevilla-Noarbe; Anže Slosar; Sherry H. Suyu; J. Anthony Tyson; Peter Yoachim

arXiv · 1812.00515

Optimizing the LSST Observing Strategy for Dark Energy Science: DESC Recommendations for the Wide-Fast-Deep Survey

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Abstract

Cosmology is one of the four science pillars of LSST, which promises to be transformative for our understanding of dark energy and dark matter. The LSST Dark Energy Science Collaboration (DESC) has been tasked with deriving constraints on cosmological parameters from LSST data. Each of the cosmological probes for LSST is heavily impacted by the choice of observing strategy. This white paper is written by the LSST DESC Observing Strategy Task Force (OSTF), which represents the entire collaboration, and aims to make recommendations on observing strategy that will benefit all cosmological analyses with LSST. It is accompanied by the DESC DDF (Deep Drilling Fields) white paper (Scolnic et al.). We use a variety of metrics to understand the effects of the observing strategy on measurements of weak lensing, large-scale structure, clusters, photometric redshifts, supernovae, strong lensing and kilonovae. In order to reduce systematic uncertainties, we conclude that the current baseline observing strategy needs to be significantly modified to result in the best possible cosmological constraints. We provide some key recommendations: moving the WFD (Wide-Fast-Deep) footprint to avoid regions of high extinction, taking visit pairs in different filters, changing the 2x15s snaps to a single exposure to improve efficiency, focusing on strategies that reduce long gaps (>15 days) between observations, and prioritizing spatial uniformity at several intervals during the 10-year survey.

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Michelle Lochner, Daniel M. Scolnic, Humna Awan, Nicolas Regnault, Philippe Gris, Rachel Mandelbaum, Eric Gawiser, Husni Almoubayyed, Christian N. Setzer, Simon Huber, Melissa L. Graham, Renée Hložek, Rahul Biswas, Tim Eifler, Daniel Rothchild, Tarek Allam Jr, Jonathan Blazek, Chihway Chang, Thomas Collett, Ariel Goobar, Isobel M. Hook, Mike Jarvis, Saurabh W. Jha, Alex G. Kim, Phil Marshall, Jason D. McEwen, Marc Moniez, Jeffrey A. Newman, Hiranya V. Peiris, Tanja Petrushevska, Jason Rhodes, Ignacio Sevilla-Noarbe, Anže Slosar, Sherry H. Suyu, J. Anthony Tyson, Peter Yoachim. 2018-11-30. Optimizing the LSST Observing Strategy for Dark Energy Science: DESC Recommendations for the Wide-Fast-Deep Survey. https://arxiv.org/abs/1812.00515

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