Confronting semi-analytic galaxy models with galaxy-matter correlations observed by CFHTLenS

Saghiha, Hananeh; Simon, Patrick; Schneider, Peter; Hilbert, Stefan

doi:10.1051/0004-6361/201629608

Cited by 16 publications

(31 citation statements)

References 49 publications

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“…To test our reconstruction technique, we employ a fiducial survey with a sky coverage of ∼ 1000 deg 2 , and a photometry and a survey depth as in CFHTLenS. To construct realistic samples of lenses and sources, we have prepared mock catalogues that are consistent with those used in SES13 and Saghiha et al (2017). Despite some variations in survey depth and area, these survey parameters are similar to the ongoing Kilo-Degree Survey (KiDS), Dark Energy Survey (DES), or the survey with the Hyper Suprime-Cam (Kuijken et al 2015;Becker et al 2016;Aihara et al 2017).…”

Section: Discussionmentioning

confidence: 99%

“…These SAMs are the H15 mocks that are also used in Saghiha et al (2017). The Millennium Simulation (MS) is a N-body simulation of the CDM density field inside a comoving cubic volume of 500 h −1 Mpc side length, and it has a spatial resolution of 5 h −1 kpc sampled by 10 10 mass particles.…”

Section: Samples Of Lens Galaxiesmentioning

confidence: 99%

“…We then select galaxies from the mocks to emulate the selection in redshift and stellar mass in Simon et al (2013), SES13 henceforth. Details on the emulation process can be found in Saghiha et al (2017). We give only a brief summary here.…”

Section: Samples Of Lens Galaxiesmentioning

confidence: 99%

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Scale dependence of galaxy biasing investigated by weak gravitational lensing: An assessment using semi-analytic galaxies and simulated lensing data

Simon¹,

Hilbert²

2018

A&A

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Galaxies are biased tracers of the matter density on cosmological scales. For future tests of galaxy models, we refine and assess a method to measure galaxy biasing as function of physical scale k with weak gravitational lensing. This method enables us to reconstruct the galaxy bias factor b(k) as well as the galaxy-matter correlation r(k) on spatial scales between 0.01 h Mpc for redshift-binned lens galaxies below redshift z 0.6. In the refinement, we account for an intrinsic alignment of source ellipticities, and we correct for the magnification bias of the lens galaxies, relevant for the galaxy-galaxy lensing signal, to improve the accuracy of the reconstructed r(k). For simulated data, the reconstructions achieve an accuracy of 3 − 7% (68% confidence level) over the above k-range for a survey area and a typical depth of contemporary ground-based surveys. Realistically the accuracy is, however, probably reduced to about 10 − 15%, mainly by systematic uncertainties in the assumed intrinsic source alignment, the fiducial cosmology, and the redshift distributions of lens and source galaxies (in that order). Furthermore, our reconstruction technique employs physical templates for b(k) and r(k) that elucidate the impact of central galaxies and the halo-occupation statistics of satellite galaxies on the scale-dependence of galaxy bias, which we discuss in the paper. In a first demonstration, we apply this method to previous measurements in the Garching-Bonn-Deep Survey and give a physical interpretation of the lens population.

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Section: Discussionmentioning

confidence: 99%

Section: Samples Of Lens Galaxiesmentioning

confidence: 99%

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Scale dependence of galaxy biasing investigated by weak gravitational lensing: An assessment using semi-analytic galaxies and simulated lensing data

Simon¹,

Hilbert²

2018

A&A

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“…It is one of various SAMs that have been implemented on the MR (see e.g. Guo et al 2011;Bower et al 2006), but as Saghiha et al (2017) have shown, this model agrees particularly well with measurements of GGL and G3L in CFHTLenS. To simulate the selection function of observations, we apply a redshift and flux limit on our lens samples.…”

Section: Simulated Data Based On the Mrmentioning

confidence: 74%

Measuring galaxy-galaxy-galaxy-lensing with higher precision and accuracy

Laila

Simon

Schneider

et al. 2020

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Context. Galaxy-galaxy-galaxy lensing (G3L) is a powerful tool for constraining the three-point correlation between the galaxy and the matter field and thereby models of galaxy evolution. Aims. We propose three improvements to current measurements of G3L, designed to improve the precision and the accuracy by using the galaxies' redshifts and removing biases of the estimator. We further show how to account for lens galaxy magnification by the cosmic large-scale structure and how to convert the G3L signal from angular to physical scales.Methods. The improvements are tested on simple mock data and simulated data based on the Millennium Run with an implemented semi-analytic model of galaxies. Results. Our improvements increase the signal-to-noise ratio by on average 35 % at angular scales between 0. 1 and 10 and physical scales between 0.02 and 2 h −1 Mpc. They also remove the bias of the G3L estimator at angular scales below 1 , which was originally up to 40 %. The signal due to lens magnification is approximately 10 % of the total signal.

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“…As discussed in Saghiha et al (2012) and recently shown by Saghiha et al (2017, hereafter S17) galaxy-galaxy-galaxy lensing can test SAMs by comparing model predictions for the average matter density around galaxy pairs to measurements. The analysis in S17 is based on the CFHTLenS 1 measurements in Simon et al (2013), S13 herafter, and uses lens galaxies with stellar masses between ∼ 10 9 − 10 11 M and redshifts below z 0.6.…”

Section: Introductionmentioning

confidence: 96%

Comparison of the excess mass around CFHTLenS galaxy-pairs to predictions from a semi-analytic model using galaxy-galaxy-galaxy lensing

Simon

Saghiha

Hilbert

et al. 2019

A&A

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The matter environment of galaxies is connected to the physics of galaxy formation and evolution. In particular, the average matter distribution around galaxy pairs is a strong test for galaxy models. Utilising galaxy-galaxy-galaxy lensing as a direct probe, we map out the distribution of correlated surface mass-density around galaxy pairs in the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS). We compare, for the first time, these so-called excess mass maps to predictions provided by a recent semianalytic model, which is implanted within the dark-matter Millennium Simulation. We analyse galaxies with stellar masses between 10 9 − 10 11 M in two photometric redshift bins, for lens redshifts z 0.6. The projected separation of the galaxy pairs ranges between 170 − 300 h −1 kpc, thereby focusing on pairs inside groups and clusters. To allow us a better interpretation of the maps, we discuss the impact of chance pairs, i.e., galaxy pairs that appear close to each other in projection only. We introduce an alternative correlation map that is less affected by projection effects but has a lower signal-to-noise ratio. Our tests with synthetic data demonstrate that the patterns observed in both types of maps are essentially produced by correlated pairs which are close in redshift (∆z 5 × 10 −3 ). We also verify the excellent accuracy of the map estimators. In an application to the galaxy samples in the CFHTLenS, we obtain a 3σ−6σ significant detection of the excess mass and an overall good agreement with the galaxy model predictions. There are, however, a few localised spots in the maps where the observational data disagrees with the model predictions on a ≈ 3.5σ confidence level. Although we have no strong indications for systematic errors in the maps, this disagreement may be related to the residual B-mode pattern observed in the average of all maps. Alternatively, misaligned galaxy pairs inside dark matter halos or lensing by a misaligned distribution of the intra-cluster gas might also cause the unanticipated bulge in the distribution of the excess mass between lens pairs.

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Confronting semi-analytic galaxy models with galaxy-matter correlations observed by CFHTLenS

Cited by 16 publications

References 49 publications

Scale dependence of galaxy biasing investigated by weak gravitational lensing: An assessment using semi-analytic galaxies and simulated lensing data

Scale dependence of galaxy biasing investigated by weak gravitational lensing: An assessment using semi-analytic galaxies and simulated lensing data

Measuring galaxy-galaxy-galaxy-lensing with higher precision and accuracy

Comparison of the excess mass around CFHTLenS galaxy-pairs to predictions from a semi-analytic model using galaxy-galaxy-galaxy lensing

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