We use a high-resolution $N$-body simulation to investigate the influence of background galaxy properties, including redshift, size, shape and clustering, on the efficiency of forming giant arcs by gravitational lensing of rich galaxy clusters. Two large sets of ray-tracing simulations are carried out for 10 massive clusters at two redshifts, i.e. $z_{\rm l} \sim 0.2$ and 0.3. The virial mass ($M_{\rm vir}$) of the simulated lens clusters at $z\sim0.2$ ranges from $6.8\times10^{14} h^{-1} {M_{\odot}}$ to $1.1\times 10^{15} h^{-1} M_{\odot}$. The information of background galaxies brighter than 25 magnitude in the $I$-band is taken from Cosmological Evolution Survey (COSMOS) imaging data. Around $1.7\times 10^5$ strong lensing realizations with these images as background galaxies have been performed for each set. We find that the efficiency for forming giant arcs for $z_{\rm l}=0.2$ clusters is broadly consistent with observations. The efficiency of producing giant arcs by rich clusters is weakly dependent on the source size and clustering. Our principal finding is that a small proportion ($\sim 1/3$) of galaxies with elongated shapes (e.g. ellipticity $ε=1-b/a>0.5$) can boost the number of giant arcs substantially. Compared with recent studies where a uniform ellipticity distribution from 0 to 0.5 is used for the sources, the adoption of directly observed shape distribution increases the number of giant arcs by a factor of $\sim2$. Our results indicate that it is necessary to account for source information and survey parameters (such as point-spread-function, seeing) to make correct predictions of giant arcs and further to constrain the cosmological parameters.(abridged)
Galaxy-Galaxy Weak Lensing Measurements from SDSS: I. Image Processing and Lensing signals
作为斯隆数字巡天数据发布7(SDSS DR 7)的星系-星系透镜研究系列中的第一篇论文,我们提出了我们的图像处理流水线,该流水线校正了主要由点扩散函数(PSF)引入的系统学。利用该流水线对SDSS DR 7成像数据进行了$r$波段的处理,生成了包含各星系形状信息的背景星系表。基于我们自己的形状测量的星系图像从SDSS DR 7,我们提取的星系星系(GG)透镜信号周围的前景分光星系在不同的光度和恒星质量。总体信号与SDSS DR 4中\citet{Mandelbaum2005, Mandelbaum2006}获得的信号一致。本文的结果具有较高的信噪比,这是由于比SDSS DR 4更大的调查区域,证实了更多的发光/质量星系具有更强的GG透镜信号。我们还将前景星系分为红/蓝和恒星形成/淬火子样本,并分别测量了它们的GG透镜信号。我们发现,在一个特定的恒星质量/光度,红色/淬火星系有相对较强的GG透镜信号比他们的同行,特别是在大半径。这些GG透镜信号可以用来探测星系晕质量关系及其在晕占据或条件光度函数框架中的环境依赖性。
Galaxy-CMB and galaxy-galaxy lensing on large scales: sensitivity to primordial non-Gaussianity
一个令人信服的检测原始非高斯的局部形式的双谱,其幅度是由fNL参数,提供了一个强大的测试膨胀。本文计算了由fNL引起的弱透镜-星系-星系透镜和星系-宇宙微波背景(CMB)互相关的两点互相关统计量的修正。推导并计算了包含宇宙方差项的星系-星系透镜效应协方差矩阵。我们专注于大尺度(l<100)的剪切测量的形状噪声变得无关紧要,宇宙方差占主导地位的误差预算。对于适度的非高斯性,fNL=+/-50,在R~300 Mpc的尺度上可以看到星系-星系透镜信号在10%水平上的变化,并且随着\propto R ^2的增大而迅速增长。我们还看到了在~150 Mpc的物质功率谱中重子声学振荡特征的清晰特征,这可以通过下一代透镜实验来测量。此外,我们可以探测本地形式的原始非高斯性的星系CMB透镜信号通过关联的高z星系的CMB重建的透镜势。例如,对于fNL=+/-50,我们发现星系-CMB透镜互功率谱在l~40处被修改了~10%,在l~10处被修改了2倍,对于z=2的星系群,偏差为2。对于z值较大的高度偏置的星系群,这种影响更大;因此,与CMB交叉相关的高z星系巡天提供了另一种原始非高斯性的探测。
A systematic study of projection biases in the Weak Lensing analysis of cosmic shear and the combination of galaxy clustering and galaxy-galaxy lensing
Galaxy-galaxy weak-lensing measurement from SDSS: II. host halo properties of galaxy groups
作为使用斯隆数字巡天数据发布7(SDSS DR 7)研究星系星系透镜信号的系列文章的第二篇,我们提出了我们对星系群周围透镜信号的测量和建模。我们将这些星系群分成4个晕质量仓,并测量了4个不同晕中心示踪物周围的信号:最亮中心星系(BCG)、亮度加权中心、数量加权中心和X射线峰值位置。对于X射线和SDSS DR 7交叉识别的组,我们进一步将组分为低和高X射线发射子样品,这两个子样品都分配有两个晕中心示踪剂,BCG和X射线峰位置。星系-星系透镜信号表明,在四个候选星系中,BCGs是最好的晕心示踪剂。我们使用四个贡献的组合模型的透镜信号:偏心NFW主机晕配置文件,子晕的贡献,恒星的贡献,并预计2晕术语。我们对5个参数的后验进行采样,即,通过MCMC软件包使用星系-星系透镜信号计算晕质量、浓度、偏心距离、次晕质量和次晕分数。在考虑到采样效应(例如爱丁顿偏差)后,我们发现从透镜信号获得的最佳拟合晕质量与基于丰度匹配方法在群目录中获得的质量非常一致,除了最低质量仓。主题词:(宇宙学:)引力透镜,星系:星系团:一般
We present weak lensing mass estimates for a sample of 458 galaxy clusters from the redMaPPer Sloan Digital Sky Survey DR8 catalogue using Hyper Suprime-Cam weak lensing data. We develop a method to quickly estimate cluster masses from weak lensing shear and use this method to estimate weak lensing masses for each of the galaxy clusters in our sample. Subsequently, we constrain the mass-richness relation as well as the intrinsic scatter between the cluster richness and the measured weak lensing masses. When calculating the mass-richness relation for all clusters with a richness $λ>20$, we find…
Cross-correlation between cosmic microwave background lensing and galaxy intrinsic alignment as a contaminant to gravitational lensing cross-correlated probes of the universe
Galaxy-galaxy(-galaxy) lensing as a sensitive probe of galaxy evolution
引力透镜效应为研究星系的质量环境提供了多种途径。我们研究如何星系星系(星系)透镜可以用来测试模型的星系形成和演化。我们考虑了两个基于Millennium Run N体模拟的半解析星系形成模型:Bower et al.(2006)的Durham模型和Guo et al.(2011)的Garching模型。我们生成模拟透镜观测的两个模型,然后采用快速傅里叶变换方法来计算二阶和三阶孔径统计在模拟领域的各种星系样本。我们发现,这两种模型预测定性相似的孔径信号,但有很大的定量差异。达勒姆模型预测的振幅一般较大。在这两个模型中,红色星系比蓝色星系表现出更强的孔径信号。使用这些孔径测量,并假设一个线性确定性的偏差模型,我们测量红,蓝星系样本的相对偏差比。我们发现,线性确定性偏差是不足以描述的相对集群模型星系低于10角分角尺度。将星系划分为光度箱,孔径信号随着较亮星系光度的降低而降低,但随着较暗星系光度的降低而再次增加。这种增加很可能是由于模型预测的大质量星系团和星系团晕中有太多暗淡的卫星星系造成的。我们的研究表明,星系-星系(-星系)透镜效应是研究星系演化的灵敏探针。
Cross-correlations between galaxy weak lensing (WL) and Cosmic Microwave Background (CMB) lensing are a powerful tool to probe matter fluctuations at intermediate redshifts and to detect residual systematics in either probe. In this paper, we study the cross-correlation of galaxy WL from the Hyper Suprime-Cam Subaru Strategic Program (HSC) first data release and CMB lensing from the final Planck data release, for HSC source galaxies at 0.3< z < 1.5. HSC is the deepest Stage-III galaxy WL survey, and provides both a great opportunity to study the high-redshift universe and new challenges relate…
We perform a thorough examination of the neutrino mass ($M_ν$) constraints achievable by combining future spectroscopic galaxy surveys with cosmic microwave background (CMB) experiments, focusing on the contribution of CMB lensing and galaxy-CMB lensing. CMB lensing can help by breaking the $M_ν$-curvature degeneracy when combined with baryon acoustic oscillation (BAO)-only measurements, but we demonstrate this combination wastes a great deal of constraining power, as the broadband shape of the power spectrum contributes significantly to constraints. We also expand on previous work to demonstr…
Reconstruction of small-scale galaxy cluster substructure with lensing flexion
我们从模拟的引力透镜数据集,包括强透镜,弱透镜剪切,和测量的二次图像失真-弯曲的星系团规模的质量分布的重建。构造透镜数据以在具有和不具有屈曲的质量重建之间进行直接比较。我们表明,在没有屈曲测量,显着的星系群规模的子结构可以保持未检测到的重建质量配置文件,并由此产生的配置文件低估了孔径质量的子结构区域的$\sim25-40\%$。当包括屈曲时,可以在小于10 \arcsec的角分辨率下检测到质量为$\sim3\times10^{12}$ M $_\odot$的亚晕。通过屈曲重建的轮廓的孔径质量与输入分布值匹配,误差在$\sim13\%$内,包括统计误差和分散。这表明了重要的约束,屈曲测量放置在子结构的星系团和它的效用,用于生产高保真质量重建。
Residual foreground contamination by thermal Sunyaev-Zeldovich (tSZ) effect from galaxy clusters in cosmic microwave background (CMB) maps propagates into the reconstructed CMB lensing field, and thus biases the intrinsic cross-correlation between CMB lensing and large-scale structure (LSS). Through stacking analysis, we show that residual tSZ contamination causes an increment of lensing convergence in the central part of the clusters and a decrement of lensing convergence in the cluster outskirts. We quantify the impact of residual tSZ contamination on cross-correlations between the Planck 20…
We derive an estimator for the lensing potential from galaxy number counts which contains a linear and a quadratic term. We show that this estimator has a much larger signal-to-noise ratio than the corresponding estimator from intensity mapping. This is due to the additional lensing term in the number count angular power spectrum which is present already at linear order. We estimate the signal-to-noise ratio for future photometric surveys. Particularly at high redshifts, $z\gtrsim 1.5$, the signal to noise ratio can become of order 30. Therefore, the number counts in photometric surveys would …
Weak lensing, Big Magnification: Recovering hidden lensing information from galaxy positions
Institute of Space Sciences (ICE, CSIC)(空间科学研究所);Universitat Autònoma de Barcelona (UAB)(巴塞罗那自治大学);Institut de Física d’Altes Energies (IFAE)(高能物理研究所);The Barcelona Institute of Science and Technology(巴塞罗那科学技术研究院)
We constrain the redshift dependence of gas pressure bias $\left\langle b_{y} P_{\mathrm{e}}\right\rangle$ (bias-weighted average electron pressure), which characterises the thermodynamics of intergalactic gas, through a combination of cross-correlations between galaxy positions and the thermal Sunyaev-Zeldovich (tSZ) effect, as well as galaxy positions and the gravitational lensing of the cosmic microwave background (CMB). The galaxy sample is from the fourth data release of the Kilo-Degree Survey (KiDS). The tSZ $y$ map and the CMB lensing map are from the {\textit{Planck}} 2015 and 2018 dat…
We demonstrate the utility and constraining power of a new statistic for investigating galaxy bias: the galaxy-lensing phase difference. The statistic consists in taking the differences of the phases of the harmonic wave-modes between the weak lensing convergence field and the galaxy count field. We use dark matter simulations populated with galaxies up to redshift $z=1$ to test the performance of this estimator. We find that phase differences are sensitive to the absolute value of the second order bias ($c_2=b_2/b_1$), and demonstrate why this is the case. For a $\sim$1500 sq. deg. galaxy sur…
Strong gravitational lensing provides unique opportunities to investigate the mass distribution at the cores of galaxy clusters and to study high redshift galaxies. Using $94$ strong lensing models of $74$ cluster fields from the \textit{Hubble} Frontier Fields (HFF), Reionization Lensing Cluster Survey (RELICS), and Sloan Giant Arcs Survey (SGAS), modeled with three parametric approaches, we evaluate the lensing strength of each cluster (area with $|μ|\geq3$ for $z_s=9$). We assess how large scale mass, projected inner core mass, and the inner slope of the projected mass density profile relat…
Photometric redshift requirements for lens galaxies in galaxy-galaxy lensing analyses
弱引力透镜是研究星系形成和宇宙学的重要工具。在这里,我们量化的影响,使用光度红移(photo-z)在星系星系透镜,无论是源和镜头,无论是直接的目标,使用星系与photo-z作为镜头在斯隆数字巡天(SDSS),并作为一个示范的方法,为大型,即将到来的弱透镜调查,将由必然的主导镜头样本与photo-z。我们计算了透镜质量校准中的偏差以及绝对幅度的结果(即,k-校正)和恒星质量的估计,SDSS数据发布8(DR 8)星系的大样本。在SDSS DR 8 ugriz光度计上用基于模板的光z代码ZEBRA获得红移。我们组装和校准样品(~ 9 k光谱红移从四个调查),以获得光度红移误差和透镜偏差对应于我们的完整的SDSS DR 8镜头和源目录。我们对校准样品的测试还突出了当光谱校准覆盖其足迹的一小部分时成像调查中观察条件的影响;校准场中的非典型成像条件可能导致关于完整调查的照片z的错误结论。对于SDSS DR 8星表,透镜星表和源星表的σ_z/(1+z)分别为0.096和0.113,通量极限分别为r=21和r=21.8。我们还探讨了系统的不确定性时,使用源photo-z的透镜信号校准,镜头和源photo-z;鉴于现有的训练样本的大小,我们可以限制透镜信号校准(因此归一化的表面质量密度)分别在2%和4%。[删节]
We examine the impact of fiber assignment on the measurement of galaxy clustering and its cross correlation with weak lensing fields. Unlike the past spectroscopic galaxy surveys such as Baryon Oscillation Spectroscopic Survey (BOSS), currently ongoing spectroscopic galaxy surveys such as Prime Focus Spectrograph (PFS) and Dark Energy Spectroscopic Instrument (DESI) suffer from the fiber assignment artifacts more severely because there are more target galaxies than available fibers. The previous studies found that the fiber assignment suppresses the amplitude of the galaxy power spectrum at al…