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arXiv · 1910.05336

KiDS+VIKING-450 and DES-Y1 combined: Mitigating baryon feedback uncertainty with COSEBIs

Marika Asgari·Tilman Tröster·Catherine Heymans·Hendrik Hildebrandt·Jan Luca van den Busch·Angus H. Wright·Ami Choi·Thomas Erben·Benjamin Joachimi·Shahab Joudaki·Arun Kannawadi·Konrad Kuijken·Chieh-An Lin·Peter Schneider·Joe Zuntz
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Abstract

We present cosmological constraints from a joint cosmic shear analysis of the Kilo-Degree Survey (KV450) and the Dark Energy Survey (DES-Y1), conducted using Complete Orthogonal Sets of E/B-Integrals (COSEBIs). With COSEBIs we isolate any B-modes which have a non-cosmic shear origin and demonstrate the robustness of our cosmological E-mode analysis as no significant B-modes are detected. We highlight how COSEBIs are fairly insensitive to the amplitude of the non-linear matter power spectrum at high $k$-scales, mitigating the uncertain impact of baryon feedback in our analysis. COSEBIs, therefore, allow us to utilise additional small-scale information, improving the DES-Y1 joint constraints on $S_8=σ_8(Ω_{\rm m}/0.3)^{0.5}$ and $Ω_{\rm m}$ by $20\%$. Adopting a flat $Λ$CDM model we find $S_8=0.755^{+0.019}_{-0.021}$, which is in $3.2σ$ tension with the Planck Legacy analysis of the cosmic microwave background.

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Marika Asgari, Tilman Tröster, Catherine Heymans, Hendrik Hildebrandt, Jan Luca van den Busch, Angus H. Wright, Ami Choi, Thomas Erben, Benjamin Joachimi, Shahab Joudaki, Arun Kannawadi, Konrad Kuijken, Chieh-An Lin, Peter Schneider, Joe Zuntz. 2020-01-21. KiDS+VIKING-450 and DES-Y1 combined: Mitigating baryon feedback uncertainty with COSEBIs. https://doi.org/10.1051/0004-6361%2F201936512

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