Cosmic shear cosmology beyond two-point statistics: a combined peak count and correlation function analysis of DES-Y1

Journal Article · Sat Jun 12 00:00:00 EDT 2021 · Monthly Notices of the Royal Astronomical Society

DOI:https://doi.org/10.1093/mnras/stab1623· OSTI ID:1808217

Harnois-Déraps, Joachim  ^[1]; Martinet, Nicolas ^[2]; Castro, Tiago  ^[3]; Dolag, Klaus ^[4]; Giblin, Benjamin  ^[5]; Heymans, Catherine ^[6]; Hildebrandt, Hendrik ^[7]; Xia, Qianli ^[5]

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1. Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool L3 5RF, UK, Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Blackford Hill, Scotland EH9 3HJ, UK, School of Mathematics, Statistics and Physics, Newcastle University, Herschel Building, Newcastle-upon-Tyne NE1 7RU, UK
2. Aix-Marseille Univ, CNRS, CNES, LAM, F-13013 Marseille, France
3. Dipartimento di Fisica, Sezione di Astronomia, Università di Trieste, Via Tiepolo 11, I-34143 Trieste, Italy, INAF - Osservatorio Astronomico di Trieste, via Tiepolo 11, I-34131 Trieste, Italy, IFPU - Institute for Fundamental Physics of the Universe, via Beirut 2, I-34151 Trieste, Italy, INFN - Sezione di Trieste, I-34100 Trieste, Italy
4. University Observatory Munich, Scheinerstr. 1, D-81679 Munich, Germany, Max-Planck-Institut fur Astrophysik, Karl-Schwarzschild Strasse 1, D-85748 Garching, Germany
5. Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Blackford Hill, Scotland EH9 3HJ, UK
6. Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Blackford Hill, Scotland EH9 3HJ, UK, Ruhr-University Bochum, Faculty of Physics and Astronomy, Astronomical Institute (AIRUB), German Centre for Cosmological Lensing, D-44780 Bochum, Germany
7. Ruhr-University Bochum, Faculty of Physics and Astronomy, Astronomical Institute (AIRUB), German Centre for Cosmological Lensing, D-44780 Bochum, Germany

ABSTRACT We constrain cosmological parameters from a joint cosmic shear analysis of peak-counts and the two-point shear correlation functions, as measured from the Dark Energy Survey (DES-Y1). We find the structure growth parameter $$S_8\equiv \sigma _8\sqrt{\Omega _{\rm m}/0.3} = 0.766^{+0.033}_{-0.038}$$ which, at 4.8 per cent precision, provides one of the tightest constraints on S8 from the DES-Y1 weak lensing data. In our simulation-based method we determine the expected DES-Y1 peak-count signal for a range of cosmologies sampled in four w cold dark matter parameters (Ωm, σ8, h, w0). We also determine the joint covariance matrix with over 1000 realizations at our fiducial cosmology. With mock DES-Y1 data we calibrate the impact of photometric redshift and shear calibration uncertainty on the peak-count, marginalizing over these uncertainties in our cosmological analysis. Using dedicated training samples we show that our measurements are unaffected by mass resolution limits in the simulation, and that our constraints are robust against uncertainty in the effect of baryon feedback. Accurate modelling for the impact of intrinsic alignments on the tomographic peak-count remains a challenge, currently limiting our exploitation of cross-correlated peak counts between high and low redshift bins. We demonstrate that once calibrated, a fully tomographic joint peak-count and correlation functions analysis has the potential to reach a 3 per cent precision on S8 for DES-Y1. Our methodology can be adopted to model any statistic that is sensitive to the non-Gaussian information encoded in the shear field. In order to accelerate the development of these beyond-two-point cosmic shear studies, our simulations are made available to the community upon request.

• Sponsoring Organization: USDOE
• OSTI ID: 1808217
• Journal Information: Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Vol. 506 Journal Issue: 2; ISSN 0035-8711
• Publisher: Oxford University Press
• Country of Publication: United Kingdom
• Language: English