Testing the reliability of weak lensing cluster detections

Pace, Francesco; Maturi, M.; Meneghetti, M.; Bartelmann, Matthias; Moscardini, L.; Dolag, K.

doi:10.1051/0004-6361:20077217

Cited by 37 publications

(54 citation statements)

References 39 publications

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“…For the optimal filter, the contribution by large-scale structures is low on all filter scales, while they typically contribute substantially for other filters. This confirms previous results with a different approach (Maturi et al 2005;Dietrich et al 2007;Pace et al 2007). -Taken together, large-scale structure and galaxy noise contribute the majority of detections up to signal-to-noise ratios between 3-5.…”

Section: Resultssupporting

confidence: 92%

“…Hennawi & Spergel 2005). An application of this filter to the GaBoDS survey (Schirmer et al 2003) was presented in Maturi et al (2007), while a detailed comparison of these three filters was performed by Pace et al (2007) by means of numerical ray-tracing simulations. They found that the optimal linear filter given by Eq.…”

Section: Weak Lensing Filtersmentioning

confidence: 99%

“…where σ = 0.25 (for further detail, see Pace et al 2007). Synthetic galaxy catalogues produced in this way are finally analysed with the aperture mass (Eq.…”

Section: Numerical Simulationsmentioning

confidence: 99%

“…For a statistical analysis of the weak-lensing detections and their relation to the numerical simulations structures, see Pace et al (2007).…”

Section: Numerical Simulationsmentioning

confidence: 99%

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An analytic approach to number counts of weak-lensing peak detections

Maturi¹,

Angrick²,

Pace³

et al. 2010

A&A

Self Cite

102

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We apply an analytic method to predict peak counts in weak-lensing surveys. It is based on the theory of Gaussian random fields and suitable to quantify the level of detections caused by chance projections of large-scale structures as well as the shape and shot noise contributed by the background galaxies. A simple analytical recipe is given to compute the signal-to-noise distribution of those detections. We compare our method to peak counts obtained from numerical ray-tracing simulations and find good agreement at the expected level. The number of peak detections depends substantially on the shape and size of the filter applied to the gravitational shear field. We confirm that weak-lensing peak counts are dominated by spurious detections up to signal-to-noise ratios of 3-5 and that most filters yield only a few detections per square degree above this level, while a filter optimised for suppressing large-scale structure noise returns up to an order of magnitude more. Galaxy shape noise and noise from large-scale structures cannot be treated as two independent components since the two contributions add in a non-trivial way.

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Section: Resultssupporting

confidence: 92%

Section: Weak Lensing Filtersmentioning

confidence: 99%

“…where σ = 0.25 (for further detail, see Pace et al 2007). Synthetic galaxy catalogues produced in this way are finally analysed with the aperture mass (Eq.…”

Section: Numerical Simulationsmentioning

confidence: 99%

“…For a statistical analysis of the weak-lensing detections and their relation to the numerical simulations structures, see Pace et al (2007).…”

Section: Numerical Simulationsmentioning

confidence: 99%

See 2 more Smart Citations

An analytic approach to number counts of weak-lensing peak detections

Maturi¹,

Angrick²,

Pace³

et al. 2010

A&A

Self Cite

102

View full text Add to dashboard Cite

show abstract

“…When the clusters considered are significant enough, all four kinds of counts perform as well at capturing non-Gaussianities : the power spectrum provides most of the Fisher information, and clusters help by breaking parameters degeneracies, independently of the way they are considered. Figure 3 shows that this is true for ν th 6, a safe threshold to discard false detections (Pace et al 2007). Therefore, that makes S/N peaks counts a direct and efficient probe to combine with the power spectrum, as shown e.g.…”

Section: Resultsmentioning

confidence: 86%

Optimal Capture of Non-Gaussianity in Weak-Lensing Surveys: Power Spectrum, Bispectrum, and Halo Counts

Bergé

Amara

Réfrégier

2010

ApJ

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We compare the efficiency of weak lensing-selected galaxy clusters counts and of the weak lensing bispectrum at capturing non-Gaussian features in the dark matter distribution. We use the halo model to compute the weak lensing power spectrum, the bispectrum and the expected number of detected clusters, and derive constraints on cosmological parameters for a large, low systematic weak lensing survey, by focusing on the Ω m -σ 8 plane and on the dark energy equation of state. We separate the power spectrum into the resolved and the unresolved parts of the data, the resolved part being defined as detected clusters, and the unresolved part as the rest of the field. We consider four kinds of clusters counts, taking into account different amount of information : signal-to-noise ratio peak counts; counts as a function of clusters' mass; counts as a function of clusters' redshift; and counts as a function of clusters' mass and redshift. We show that when combined with the power spectrum, those four kinds of counts provide similar constraints, thus allowing one to perform the most direct counts, signalto-noise peaks counts, and get percent level constraints on cosmological parameters. We show that the weak lensing bispectrum gives constraints comparable to those given by the power spectrum and captures non-Gaussian features as well as clusters counts, its combination with the power spectrum giving errors on cosmological parameters that are similar to, if not marginally smaller than, those obtained when combining the power spectrum with cluster counts. We finally note that in order to reach its potential, the weak lensing bispectrum must be computed using all triangle configurations, as equilateral triangles alone do not provide useful information. The appendices summarize the halo model, and the way the power spectrum and bispectrum are computed in this framework.

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Weak gravitational lensing

2001

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According to the theory of general relativity, masses deflect light in a way similar to convex glass lenses. This gravitational lensing effect is astigmatic, giving rise to image distortions. These distortions allow to quantify cosmic structures statistically on a broad range of scales, and to map the spatial distribution of dark and visible matter. We summarise the theory of weak gravitational lensing and review applications to galaxies, galaxy clusters and larger-scale structures in the Universe.

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Testing the reliability of weak lensing cluster detections

Cited by 37 publications

References 39 publications

An analytic approach to number counts of weak-lensing peak detections

An analytic approach to number counts of weak-lensing peak detections

Optimal Capture of Non-Gaussianity in Weak-Lensing Surveys: Power Spectrum, Bispectrum, and Halo Counts

Weak gravitational lensing

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