Dark Energy Survey Year 1 Results: Constraining Baryonic Physics in the Universe

(DES Collaboration), Hung-Jin Huang*, Tim Eifler, Rachel Mandelbaum, Gary M. Bernstein, Anqi Chen, Ami Choi, Juan García-Bellido, Dragan Huterer, Elisabeth Krause, Eduardo Rozo, Sukhdeep Singh, Sarah Bridle, Joseph DeRose, Jack Elvin-Pole, Xiao Fang, Oliver Friedrich, Marco Gatti, Enrique Gaztanaga, Daniel GruenWill Hartley, Ben Hoyle, Mike Jarvis, Niall MacCrann, Markus Rau, Vivian Miranda, Judit Prat, Carles Sánchez, Simon Samuroff, Michael Troxel, Joe Zuntz, Tim Abbott, Michel Aguena, James Annis, Santiago Avila, Matthew Becker, Emmanuel Bertin, David Brooks, David Burke, Aurelio Carnero Rosell, Matias Carrasco Kind, Jorge Carretero, Francisco Javier Castander, Luiz da Costa, Juan De Vicente, Jörg Dietrich, Peter Doel, Spencer Everett, Brenna Flaugher, Pablo Fosalba, Josh Frieman, Robert Gruendl, Gaston Gutierrez, Samuel Hinton, Klaus Honscheid, David James, Kyler Kuehn, Ofer Lahav, Marcos Lima, Marcio Maia, Jennifer Marshall, Felipe Menanteau, Ramon Miquel, Francisco Paz-Chinchón, Andrés Plazas Malagón, Kathy Romer, Aaron Roodman, Eusebio Sanchez, Vic Scarpine, Santiago Serrano, Ignacio Sevilla, Mathew Smith, Marcelle Soares-Santos, Eric Suchyta, Molly Swanson, Gregory Tarle, Diehl H. Thomas, Jochen Weller

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

Measurements of large-scale structure are interpreted using theoretical predictions for the matter distribution, including potential impacts of baryonic physics. We constrain the feedback strength of baryons jointly with cosmology using weak lensing and galaxy clustering observables (3 × 2pt) of Dark Energy Survey (DES) Year 1 data in combination with external information from baryon acoustic oscillations (BAO) and Planck cosmic microwave background polarization. Our baryon modelling is informed by a set of hydrodynamical simulations that span a variety of baryon scenarios; we span this space via a Principal Component (PC) analysis of the summary statistics extracted from these simulations. We show that at the level of DES Y1 constraining power, one PC is sufficient to describe the variation of baryonic effects in the observables, and the first PC amplitude (Q1) generally reflects the strength of baryon feedback. With the upper limit of Q1 prior being bound by the Illustris feedback scenarios, we reach ∼20 per cent improvement in the constraint of S8=σ8(Ωm/0.3)0.5=0.788+0.018−0.021 compared to the original DES 3 × 2pt analysis. This gain is driven by the inclusion of small-scale cosmic shear information down to 2.5 arcmin, which was excluded in previous DES analyses that did not model baryonic physics. We obtain S8=0.781+0.014−0.015 for the combined DES Y1+Planck EE+BAO analysis with a non-informative Q1 prior. In terms of the baryon constraints, we measure Q1=1.14+2.20−2.80 for DES Y1 only and Q1=1.42+1.63−1.48 for DESY1+Planck EE+BAO, allowing us to exclude one of the most extreme AGN feedback hydrodynamical scenario at more than 2σ.
Original languageEnglish
Pages (from-to)6010-6031
Number of pages22
JournalMonthly Notices of the Royal Astronomical Society
Issue number4
Early online date15 Feb 2021
Publication statusPublished - 1 Apr 2021

Keywords / Materials (for Non-textual outputs)

  • astro-ph.CO


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