A unified analysis of four cosmic shear surveys

Journal Article · 26 October 2018 · Monthly Notices of the Royal Astronomical Society

DOI: https://doi.org/10.1093/mnras/sty2902 · OSTI ID:1478048

Chang, Chihway  ^[1]; Wang, Michael ^[2]; Dodelson, Scott ^[3]; Eifler, Tim ^[4]; Heymans, Catherine ^[5]; Jarvis, Michael ^[6]; Jee, M. James ^[7]; Joudaki, Shahab ^[8]; Krause, Elisabeth ^[4]; Malz, Alex ^[9]; Mandelbaum, Rachel ^[3]; Mohammed, Irshad ^[2]; Schneider, Michael ^[10]; Simet, Melanie ^[11]; Troxel, Michael A. ^[12]; Zuntz, Joe ^[5]

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1. Univ. of Chicago, Chicago, IL (United States)
2. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
3. Carnegie Mellon Univ., Pittsburgh, PA (United States)
4. California Inst. of Technology (CalTech), Pasadena, CA (United States)
5. Univ. of Edinburgh, Edinburgh (United Kingdom)
6. Univ. of Pennsylvania, Philadelphia, PA (United States)
7. Yonsei Univ., Seoul (Korea); Univ. of California, Davis, CA (United States)
8. Univ. of Oxford, Oxford (United Kingdom)
9. New York Univ. (NYU), New York, NY (United States)
10. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
11. California Inst. of Technology (CalTech), Pasadena, CA (United States); Univ. of California, Riverside, CA (United States)
12. The Ohio State Univ., Columbus, OH (United States)

In the past few years, several independent collaborations have presented cosmological constraints from tomographic cosmic shear analyses. These analyses differ in many aspects: the datasets, the shear and photometric redshift estimation algorithms, the theory model assumptions, and the inference pipelines. To assess the robustness of the existing cosmic shear results, we present in this paper a unified analysis of four of the recent cosmic shear surveys: the Deep Lens Survey (DLS), the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS), the Science Verification data from the Dark Energy Survey (DES-SV), and the 450 deg$$^{2}$$ release of the Kilo-Degree Survey (KiDS-450). By using a unified pipeline, we show how the cosmological constraints are sensitive to the various details of the pipeline. We identify several analysis choices that can shift the cosmological constraints by a significant fraction of the uncertainties. For our fiducial analysis choice, considering a Gaussian covariance, conservative scale cuts, assuming no baryonic feedback contamination, identical cosmological parameter priors and intrinsic alignment treatments, we find the constraints (mean, 16% and 84% confidence intervals) on the parameter $$S_{8}\equiv \sigma_{8}(\Omega_{\rm m}/0.3)^{0.5}$$ to be $$S_{8}=0.94_{-0.045}^{+0.046}$$ (DLS), $$0.66_{-0.071}^{+0.070}$$ (CFHTLenS), $$0.84_{-0.061}^{+0.062}$$ (DES-SV) and $$0.76_{-0.049}^{+0.048}$$ (KiDS-450). From the goodness-of-fit and the Bayesian evidence ratio, we determine that amongst the four surveys, the two more recent surveys, DES-SV and KiDS-450, have acceptable goodness-of-fit and are consistent with each other. Furthermore the combined constraints are $$S_{8}=0.79^{+0.042}_{-0.041}$$, which is in good agreement with the first year of DES cosmic shear results and recent CMB constraints from the Planck satellite.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), High Energy Physics (HEP)
• Contributing Organization: LSST Dark Energy Science Collaboration
• Grant/Contract Number: AC02-07CH11359; AC52-07NA27344
• OSTI ID: 1478048
• Report Number(s): FERMILAB-PUB-18-427-A; LLNL-JRNL-757794; arXiv:1808.07335; 1689428
• Journal Information: Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 3 Vol. 482; ISSN 0035-8711
• Publisher: Royal Astronomical SocietyCopyright Statement
• Country of Publication: United States
• Language: English