sunglass: a new weak-lensing simulation pipeline

• Published in: Monthly notices of the Royal Astronomical Society 2011-07, Vol.414 (3), p.2235-2245
• Main Authors: Kiessling, A., Heavens, A. F., Taylor, A. N., Joachimi, B.
• Format: Article
• Language: English
• Subjects: Astronomy; Astrophysics; Earth, ocean, space; Exact sciences and technology; gravitational lensing: weak; Gravity; large‐scale structure of Universe; methods: numerical; Stars & galaxies
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1111/j.1365-2966.2011.18540.x

A new cosmic shear analysis pipeline sunglass (Simulated UNiverses for Gravitational Lensing Analysis and Shear Surveys) is introduced. sunglass is a pipeline that rapidly generates simulated universes for weak-lensing and cosmic shear analysis. The pipeline forms suites of cosmological N-body simulations and performs tomographic cosmic shear analysis using line-of-sight integration through these simulations while saving the particle lightcone information. Galaxy shear and convergence catalogues with realistic 3D galaxy redshift distributions are produced for the purposes of testing weak-lensing analysis techniques and generating covariance matrices for data analysis and cosmological parameter estimation. We present a suite of fast medium-resolution simulations with shear and convergence maps for a generic 100 deg2 survey out to a redshift of z= 1.5, with angular power spectra agreeing with the theory to better than a few per cent accuracy up to ℓ= 103 for all source redshifts up to z= 1.5 and wavenumbers up to ℓ= 2000 for the source redshifts z≥ 1.1. At higher wavenumbers, there is a failure of the theoretical lensing power spectrum reflecting the known discrepancy of the Smith et al. fitting formula at high physical wavenumbers. A two-parameter Gaussian likelihood analysis of σ8 and Ωm is also performed on the suite of simulations, demonstrating that the cosmological parameters are recovered from the simulations and the covariance matrices are stable for data analysis. We find that any residual bias in our calculation is below our uncertainty within the 1σ confidence limits. The sunglass pipeline should be an invaluable tool in weak-lensing analysis.