Constraining the Baryonic Feedback with Cosmic Shear Using the DES Year-3 Small-Scale Measurements

Abstract

We use the small scales of the Dark Energy Survey (DES) Year-3 cosmic shear measurements, which are excluded from the DES Year-3 cosmological analysis, to constrain the baryonic feedback. To model the baryonic feedback, we adopt a baryonic correction model and use the numerical package Baccoemu to accelerate the evaluation of the baryonic nonlinear matter power spectrum. We design our analysis pipeline to focus on the constraints of the baryonic suppression effects, utilizing the implication given by a principal component analysis on the Fisher forecasts. Our constraint on the baryonic effects can then be used to better model and ameliorate the effects of baryons in producing cosmological constraints from the next generation large-scale structure surveys. We detect the baryonic suppression on the cosmic shear measurements with a ∼ 2σ significance. The characteristic halo mass for which half of the gas is ejected by baryonic feedback is constrained to be Mc > 10 13.2 h −1 M (95% C.L.). The best-fit baryonic suppression is ∼ 5% at k = 1.0Mpc h −1 and ∼ 15% at k = 5.0Mpc h −1 . Our findings are robust with respect to the assumptions about the cosmological parameters, specifics of the baryonic model, and intrinsic alignments.

Deciphering baryonic feedback with galaxy clusters

“…While the conclusion depends on the ranges of baryonic physics explored (see also [11]), they find that the uncertainties of baryonic physics are sufficiently large to remove most of the constraining power of the additional data in the most conservative setting. Further, [12][13][14] incorporate baryon correction models that alter gravity-only simulations according to a dark matter + baryon (DMB) halo model to mimic the impact of baryonic physics on matter clustering. They reanalyze survey datasets and find similar conclusions as [10], that most of the signal-to-noise on additional cosmic shear measurements relative to key cosmological analyses goes to constrain baryonic physics instead of cosmology.…”

An empirical approach to model selection: weak lensing and intrinsic alignments

“…In most cases, however, there is a relative lack of prior knowledge about the magnitude and/or scale dependence of the effects being modelled. Some examples include the impact of baryonic feedback (Osato et al 2015;Chen et al 2022;Tröster et al 2022), nonlinear structure formation (and the impact of neutrinos on it; Saito et al 2008;Bird et al 2012;Mead et al 2021;Knabenhans et al 2021) and galaxy bias (Desjacques et al 2018;Simon & Hilbert 2018;Pandey et al 2020). Here, there is clearly an argument for using the most sophisticated (physically motivated) model available.…”