CFHTLenS: a Gaussian likelihood is a sufficient approximation for a cosmological analysis of third-order cosmic shear statistics

Simon, Patrick; Semboloni, Elisabetta; Waerbeke, Ludovic Van; Hoekstra, Henk; Erben, T.; Fu, Liping; Harnois-Déraps, Joachim; Heymans, Catherine; Hildebrandt, Hendrik; Kilbinger, M.; Kitching, Thomas D.; Miller, L.; Schrabback, T.

doi:10.1093/mnras/stv339

Cited by 20 publications

(16 citation statements)

References 81 publications

(118 reference statements)

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“…The modelling at small scales is obtained including the analytical refinement based on N-body, cold dark matter only simulations (Scoccimarro & Couchman 2001; Gil-Marín et al 2012); predictions from the third moments from perturbation theory only would start departing from the T17 measurement at ∼ 30 arcmin, reaching a disagreement of 80 per cent at 5 arcmin in the first tomographic bin. This analytical refinement comes with a modelling uncertainty (Van Waerbeke et al 2001;Semboloni et al 2011;Harnois-Déraps et al 2016;Simon et al 2015), which is taken into account in our covariance matrix (see § 5.1). We test in § 6.1 that this level of accuracy of our modelling is good enough for our cosmological analysis.…”

Section: Testing Second and Third Moments Modellingmentioning

confidence: 99%

Dark Energy Survey Year 3 results: cosmology with moments of weak lensing mass maps – validation on simulations

Gatti¹,

Chang²,

Friedrich³

et al. 2020

Monthly Notices of the Royal Astronomical Society

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We present a simulated cosmology analysis using the second and third moments of the weak lensing mass (convergence) maps. The second moment, or variances, of the convergence as a function of smoothing scale contains information similar to standard shear 2-point statistics. The third moment, or the skewness, contains additional non-Gaussian information. The analysis is geared towards the third year (Y3) data from the Dark Energy Survey (DES), but the methodology can be applied to other weak lensing data sets. We present the formalism for obtaining the convergence maps from the measured shear and for obtaining the second and third moments of these maps given partial sky coverage. We estimate the covariance matrix from a large suite of numerical simulations. We test our pipeline through a simulated likelihood analyses varying 5 cosmological parameters and 10 nuisance parameters and identify the scales where systematic or modelling uncertainties are not expected to affect the cosmological analysis. Our simulated likelihood analysis shows that the combination of second and third moments provides a 1.5 percent constraint on S8 ≡ σ8(Ωm/0.3)0.5 for DES Year 3 data. This is 20 percent better than an analysis using a simulated DES Y3 shear 2-point statistics, owing to the non-Gaussian information captured by the inclusion of higher-order statistics. This paper validates our methodology for constraining cosmology with DES Year 3 data, which will be presented in a subsequent paper.

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Section: Testing Second and Third Moments Modellingmentioning

confidence: 99%

Dark Energy Survey Year 3 results: cosmology with moments of weak lensing mass maps – validation on simulations

Gatti¹,

Chang²,

Friedrich³

et al. 2020

Monthly Notices of the Royal Astronomical Society

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“…We estimate the red fraction directly from the data in each redshift bin, using the BPZ template information T B. Motivated by Simon et al (2015), we identify red galaxies as objects with T B < 1.5. For the five tomographic bins, we obtain fractions of red galaxies f red = {0.04, 0.12, 0.27, 0.18, 0.04}; we estimate f red = 0.15 for the broad bin.…”

Section: Effect Of Intrinsic Alignmentsmentioning

confidence: 99%

KiDS-450: tomographic cross-correlation of galaxy shear with Planck lensing

Harnois-Déraps

Tröster

Chisari

et al. 2017

Monthly Notices of the Royal Astronomical Society

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We present the tomographic cross-correlation between galaxy lensing measured in the Kilo Degree Survey (KiDS-450) with overlapping lensing measurements of the cosmic microwave background (CMB), as detected by Planck 2015. We compare our joint probe measurement to the theoretical expectation for a flat ΛCDM cosmology, assuming the best-fitting cosmological parameters from the KiDS-450 cosmic shear and Planck CMB analyses. We find that our results are consistent within 1σ with the KiDS-450 cosmology, with an amplitude re-scaling parameter A KiDS = 0.86 ± 0.19. Adopting a Planck cosmology, we find our results are consistent within 2σ, with A Planck = 0.68 ± 0.15. We show that the agreement is improved in both cases when the contamination to the signal by intrinsic galaxy alignments is accounted for, increasing A by ∼ 0.1. This is the first tomographic analysis of the galaxy lensing -CMB lensing cross-correlation signal, and is based on five photometric redshift bins. We use this measurement as an independent validation of the multiplicative shear calibration and of the calibrated source redshift distribution at high redshifts. We find that constraints on these two quantities are strongly correlated when obtained from this technique, which should therefore not be considered as a stand-alone competitive calibration tool.Key words: Gravitational lensing: weak -Large scale structure of Universe -Dark matter c 2016 RAS 3 www.lsst.org 4 sci.esa.int/euclid 5 Our fiducial cosmology consists of a flat ΛCDM universe in which the dark energy equation of state is set to w = −1.

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“…Weak gravitational lensing has been successfully used in a wide range of applications, including for example cosmic shear studies which are sensitive to the growth of large-scale structure (e.g. Schrabback et al 2010;Kilbinger et al 2013;Heymans et al 2013;Huff et al 2014;Kitching et al 2014;Simon et al 2015), the mass calibration of galaxy clusters (e.g. von der Linden et al 2014; Kettula et al 2015;Ford et al 2015;Hoekstra et al 2015), and constraints on the azimuthally-averaged mass profiles of galaxy matter haloes (e.g.…”

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confidence: 99%

CFHTLenS: weak lensing constraints on the ellipticity of galaxy-scale matter haloes and the galaxy-halo misalignment

Schrabback¹,

Hilbert²,

Hoekstra³

et al. 2015

Mon. Not. R. Astron. Soc.

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We present weak lensing constraints on the ellipticity of galaxy-scale matter haloes and the galaxy-halo misalignment. Using data from the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS), we measure the weighted-average ratio of the aligned projected ellipticity components of galaxy matter haloes and their embedded galaxies, f h , split by galaxy type. We then compare our observations to measurements taken from the Millennium Simulation, assuming different models of galaxy-halo misalignment. Using the Millennium Simulation we verify that the statistical estimator used removes contamination from cosmic shear. We also detect an additional signal in the simulation, which we interpret as the impact of intrinsic shape-shear alignments between the lenses and their large-scale structure environment. These alignments are likely to have caused some of the previous observational constraints on f h to be biased high. From CFHTLenS we find f h = −0.04 ± 0.25 for early-type galaxies, which is consistent with current models for the galaxy-halo misalignment predicting f h ≃ 0.20. For late-type galaxies we measure f h = 0.69 +0.37 −0.36 from CFHTLenS. This can be compared to the simulated results which yield f h ≃ 0.02 for misaligned late-type models.

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CFHTLenS: a Gaussian likelihood is a sufficient approximation for a cosmological analysis of third-order cosmic shear statistics

Cited by 20 publications

References 81 publications

Dark Energy Survey Year 3 results: cosmology with moments of weak lensing mass maps – validation on simulations

Dark Energy Survey Year 3 results: cosmology with moments of weak lensing mass maps – validation on simulations

KiDS-450: tomographic cross-correlation of galaxy shear with Planck lensing

CFHTLenS: weak lensing constraints on the ellipticity of galaxy-scale matter haloes and the galaxy-halo misalignment

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