CFHTLenS: A Weak Lensing Shear Analysis of the 3D-Matched-Filter Galaxy Clusters
Jes Ford, Ludovic Van Waerbeke, Martha Milkeraitis, Clotilde Laigle, Hendrik Hildebrandt, Thomas Erben, Catherine Heymans, Henk Hoekstra, Thomas Kitching, Yanni… 展开作者
Jes Ford, Ludovic Van Waerbeke, Martha Milkeraitis, Clotilde Laigle, Hendrik Hildebrandt, Thomas Erben, Catherine Heymans, Henk Hoekstra, Thomas Kitching, Yannick Mellier, Lance Miller, Ami Choi, Jean Coupon, Liping Fu, Michael J. Hudson, Konrad Kuijken, Naomi Robertson, Barnaby Rowe, Tim Schrabback, Malin Velander
备注:
3D-MF cluster catalog is NOW AVAILABLE at cfhtlens.org. Magnification-shear mass comparison in Figure 10. 19 pages, 10 figures. Accepted to MNRAS
We present the cluster mass-richness scaling relation calibrated by a weak lensing analysis of >18000 galaxy cluster candidates in the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS). Detected using the 3D-Matched-Filter cluster-finder of Milkeraitis et al., these cluster candidates span a wide range of masses, from the small group scale up to $\sim10^{15} M_{\odot}$, and redshifts 0.2 $\lesssim z\lesssim$ 0.9. The total significance of the stacked shear measurement amounts to 54$σ$. We compare cluster masses determined using weak lensing shear and magnification, finding the measurements in individual richness bins to yield 1$σ$ compatibility, but with magnification estimates biased low. This first direct mass comparison yields important insights for improving the systematics handling of future lensing magnification work. In addition, we confirm analyses that suggest cluster miscentring has an important effect on the observed 3D-MF halo profiles, and we quantify this by fitting for projected cluster centroid offsets, which are typically $\sim$ 0.4 arcmin. We bin the cluster candidates as a function of redshift, finding similar cluster masses and richness across the full range up to $z \sim$ 0.9. We measure the 3D-MF mass-richness scaling relation $M_{200} = M_0 (N_{200} / 20)^β$. We find a normalization $M_0 \sim (2.7^{+0.5}_{-0.4}) \times 10^{13} M_{\odot}$, and a logarithmic slope of $β\sim 1.4 \pm 0.1$, both of which are in 1$σ$ agreement with results from the magnification analysis. We find no evidence for a redshift-dependence of the normalization. The CFHTLenS 3D-MF cluster catalogue is now available at cfhtlens.org.
Constraining Multiplicative Bias in CFHTLenS Weak Lensing Shear Data
最近的一些宇宙学分析发现,来自加拿大-法国-夏威夷望远镜透镜巡天(CFHTLenS)数据的约束与来自其他数据集(如普朗克宇宙微波背景(CMB)温度各向异性)的约束之间存在紧张关系。类似地,CFHTLenS数据与普朗克CMB透镜数据的直接互相关产生了与基于普朗克或WMAP导出的宇宙学参数的预期相比非常低的振幅(Liu & Hill 2015)。这些结果的一个潜在解释是影响CFHTLenS星系形状测量的乘法偏差,从中推断出剪切。CFHTLenS管道中使用模拟来校准此类偏差,但迄今为止尚未提出数据驱动的约束。在本文中,我们将CFHTLenS星系密度图与CFHTLenS剪切图和普朗克CMB透镜图进行交叉关联,以校准CFHTLenS中的额外乘法剪切偏差(m)(超出已经应用于CFHTLenS星系剪切的乘法校正),遵循Vallinotto(2012)和Das等人建议的方法。我们分析了三个星等有限的星系样本,发现使用最深的样本(i<24)的2-4sigma证据m<1,而其他的则与m=1一致(无偏差)。这与暗星系的形状最容易受到测量偏差的影响的预期相匹配。我们的结果m基本上是独立的假设宇宙学,只有弱敏感的假设星系的偏见。我们考虑三个星系的偏见模型,发现在所有情况下,最适合的乘法剪切偏置小于统一。m~0.9的值足以使从CFHTLenS剪切两点统计推断的密度波动幅度与从普朗克CMB温度数据推断的密度波动…
Based on the cosmic shear data from the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS), Kilbinger et al. (2013) obtained a constraint on the amplitude of matter fluctuations of $σ_8({Ω_\mathrm{m}}/0.27)^{0.6}=0.79\pm0.03$ from the two-point correlation function (2PCF). This is $\approx3σ$ lower than the value $0.89\pm0.01$ derived from Planck data on cosmic microwave background (CMB) anisotropies. On the other hand, based on the same CFHTLenS data, but using the power spectrum, and performing a different analysis, Liu et al. (2015) obtained the higher value of $σ_8({Ω_\mathrm{m}}/0.2…
We analyse three public cosmic shear surveys; the Kilo-Degree Survey (KiDS-450), the Dark Energy Survey (DES-SV) and the Canada France Hawaii Telescope Lensing Survey (CFHTLenS). Adopting the COSEBIs statistic to cleanly and completely separate the lensing E-modes from the non-lensing B-modes, we detect B-modes in KiDS-450 and CFHTLenS at the level of about 2.7 $σ$. For DES- SV we detect B-modes at the level of 2.8 $σ$ in a non-tomographic analysis, increasing to a 5.5 $σ$ B-mode detection in a tomographic analysis. In order to understand the origin of these detected B-modes we measure the B-m…
The matter environment of galaxies is connected to the physics of galaxy formation and evolution. Utilising galaxy-galaxy-galaxy lensing as a direct probe, we map out the distribution of correlated surface mass-density around galaxy pairs for different lens separations 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 semi-analytic model, which is implanted within the dark-matter Millennium Simulation. We analyse galaxies with stellar masses between $10^9-10^{11}\,{\rm M}_\odot$ …
We report the first evidence for intrinsic alignment (IA) of red galaxies at $z>1$. We measure the gravitational shear-intrinsic ellipticity (GI) cross-correlation function at $z\sim1.3$ using galaxy positions from the FastSound spectroscopic survey and galaxy shapes from Canada-Hawaii-France telescope lensing survey data. Adopting the non-linear alignment model, we obtain a $2.4σ$-level detection of the IA amplitude $A^{\rm LA}=27.48_{-11.54}^{+11.53}$ (and $2.6σ$ with $A^{\rm LA}=29.43_{-11.49}^{+11.48}$ when weak-lensing contaminations are taken into account), which is larger than the value…
The combination of Galaxy-Galaxy Lensing (GGL) and Redshift Space Distortion of galaxy clustering (RSD) is a privileged technique to test General Relativity predictions, and break degeneracies between the growth rate of structure parameter $f$ and the amplitude of the linear power-spectrum $σ_8$. We perform a joint GGL and RSD analysis on 250 sq. degrees using shape catalogues from CFHTLenS and CFHT-Stripe 82, and spectroscopic redshifts from the BOSS CMASS sample. We adjust a model that includes non-linear biasing, RSD and Alcock-Paczynski effects. We find $f(z=0.57) =0.95\pm0.23$, $σ_8(z=0.5…
We report the results of $EasyCritics$, a fully automated algorithm for the efficient search of strong-lensing (SL) regions in wide-field surveys, applied to the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS). By using only the photometric information of the brightest elliptical galaxies distributed over a wide redshift range ($\smash{0.2 \lesssim z \lesssim 0.9}$) and without requiring the identification of arcs, our algorithm produces lensing potential models and catalogs of critical curves of the entire survey area. We explore several parameter set configurations in order to test …
Testing PSF Interpolation In Weak Lensing With Real Data
在弱透镜测量中,点扩散函数的重建是一个关键的过程。我们开发了一个基于真实数据和面向星系的管道,比较各种PSF重建方案的性能。利用大量的CFHTLenS数据,三类插值方案-多项式,克里格和谢泼德-的性能进行了评估。我们发现,多项式插值的最佳顺序和域执行最好的。我们使用Zhang et al.(2015)的剪切测量方法,根据乘法和加法偏差及其空间相关性量化了残余PSF重建误差对剪切恢复的影响。我们发现,PSF重建的不确定性对剪切相关性的影响,可以显着减少交叉相关的剪切估计从不同的曝光。在每次曝光时,每平方弧分仅需0.2颗星(SNR > 100)即可达到PSF插值的最佳性能,这一要求通常在CFHTlenS数据中得到满足。
Accurate reconstruction of the spatial distributions of the Point Spread Function (PSF) is crucial for high precision cosmic shear measurements. Nevertheless, current methods are not good at recovering the PSF fluctuations of high spatial frequencies. In general, the residual PSF fluctuations are spatially correlated, therefore can significantly contaminate the correlation functions of the weak lensing signals. We propose a method to correct for this contamination statistically, without any assumptions on the PSF and galaxy morphologies or their spatial distribution. We demonstrate our idea wi…
We present our results from training and evaluating a convolutional neural network (CNN) to predict galaxy shapes from wide-field survey images of the first data release of the Dark Energy Survey (DES DR1). We use conventional shape measurements as ground truth from an overlapping, deeper survey with less sky coverage, the Canada-France Hawaii Telescope Lensing Survey (CFHTLenS). We demonstrate that CNN predictions from single band DES images reproduce the results of CFHTLenS at bright magnitudes and show higher correlation with CFHTLenS at fainter magnitudes than maximum likelihood model fitt…
We explore an alternative method to the usual shear correlation function approach for the estimation of aperture mass statistics in weak lensing survey data. Our approach builds on the direct estimator method of Schneider (1998). In this paper, to test and validate the methodology, we focus on the aperture mass dispersion. After computing the signal and noise for a weighted set of measured ellipticites we show how the direct estimator can be made into a linear order algorithm that enables a fast and efficient computation. We then investigate the applicability of the direct estimator approach i…
Galaxy models predict a tight relation between the clustering of galaxies and dark matter on cosmological scales, but predictions differ notably in the details. We used this opportunity and tested two semi-analytic models by the Munich and Durham groups with data from the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS). For the test we measured the scale-dependent galaxy bias factor $b(k)$ and correlation factor $r(k)$ from linear to non-linear scales of $k\approx10\,h\,\rm Mpc^{-1}$ at two redshifts $\bar{z}=0.35,0.51$ for galaxies with stellar mass between $5\times10^9$ and $3\times…
In this manuscript of the habilitation à diriger des recherches (HDR), the author presents some of his work over the last ten years. The main topic of this thesis is cosmic shear, the distortion of images of distant galaxies due to weak gravitational lensing by the large-scale structure in the Universe. Cosmic shear has become a powerful probe into the nature of dark matter and the origin of the current accelerated expansion of the Universe. Over the last years, cosmic shear has evolved into a reliable and robust cosmological probe, providing measurements of the expansion history of the Univer…