Pan-STARRS1: Galaxy Clustering in the Small Area Survey 2
Daniel J. Farrow, Shaun Cole, N. Metcalfe, P. W. Draper, Peder Norberg, Sebastien Foucaud, W. S. Burgett, K. C. Chambers, N. Kaiser, R. P. Kudritzki, E. A. Magn… 展开作者
Daniel J. Farrow, Shaun Cole, N. Metcalfe, P. W. Draper, Peder Norberg, Sebastien Foucaud, W. S. Burgett, K. C. Chambers, N. Kaiser, R. P. Kudritzki, E. A. Magnier, P. A. Price, J. L. Tonry, C. Waters
备注：
26 pages, 28 figures. Accepted for publication in MNRAS
The Pan-STARRS1 survey is currently obtaining imaging in 5 bands (grizy) for the $3π$ steradian survey, one of the largest optical surveys ever conducted. The finished survey will have spatially varying depth, due to the survey strategy. This paper presents a method to correct galaxy number counts and galaxy clustering for this potential systematic based on a simplified signal to noise measurement. A star and galaxy separation method calibrated using realistic synthetic images is also presented, along with an approach to mask bright stars. By using our techniques on a ~69 sq. degree region of science verification data this paper shows PS1 measurements of the two point angular correlation function as a function of apparent magnitude agree with measurements from deeper, smaller surveys. Clustering measurements appear reliable down to a magnitude limit of rps<22.5. Additionally, stellar contamination and false detection issues are discussed and quantified. This work is the second of two papers which pave the way for the exploitation of the full $3π$ survey for studies of large scale structure.
The combination of galaxy-galaxy lensing (GGL) with galaxy clustering is one of the most promising routes to determining the amplitude of matter clustering at low redshifts. We show that extending clustering+GGL analyses from the linear regime down to $\sim 0.5 \, h^{-1}$ Mpc scales increases their constraining power considerably, even after marginalizing over a flexible model of non-linear galaxy bias. Using a grid of cosmological N-body simulations, we construct a Taylor-expansion emulator that predicts the galaxy autocorrelation $ξ_{\text{gg}}(r)$ and galaxy-matter cross-correlation $ξ_{\te…
Galaxy clustering provides insightful clues to our understanding of galaxy formation and evolution, as well as the universe. The redshift assignment for the random sample is one of the key steps to measure the galaxy clustering accurately. In this paper, by virtue of the mock galaxy catalogs, we investigate the effect of two redshift assignment methods on the measurement of galaxy two-point correlation functions (hereafter 2PCFs), the Vmax method and the "shuffled" method. We found that the shuffled method significantly underestimates both of the projected 2PCFs and the two-dimensional 2PCFs i…
Resolving the problem of galaxy clustering on small scales: any new physics needed?
星系团对控制星系形成和演化的物理学有很强的限制。然而，目前大多数的模型不能再现小尺度上的低质量星系团（$r<1Mpc/h$）。本文研究了几种半解析模型预测的星系团。我们首先比较了两个慕尼黑版本，Guo et al.（2011，Guo11）和De Lucia \& Blazoit（2007，DLB07）。Guo 11模型很好地再现了星系的恒星质量函数，但在小尺度上高估了低质量星系的成团。DLB07模型在小尺度上提供了更好的聚类拟合，但过度预测了恒星质量函数。这些似乎令人费解。我们发现Guo 11模型中有更多的卫星星系分布在大质量星系晕中，这是导致两个模型之间星系团簇差异的主要原因。然而，这两个模型仍然过度预测的集群在$0.1Mpc/h<r<10Mpc/h$的低质量星系。这是因为两个模型都过度预测了$30\%$在大规模晕中的卫星数量，而不是数据。实际上，DLB07模型与小尺度数据的更好的一致性是一个巧合，因为它预测了太多的低质量中心星系，这些星系不太聚集，从而降低了总的聚集。最后，我们展示了Kang et al.（2012）的半分析预测。我们发现，如果卫星星系中的超新星反馈较强，该模型可以同时拟合恒星质量函数和星系成团。我们的结论是，半解析模型现在能够解决小尺度的集群问题，而不调用任何其他新的物理或改变暗物质的属性，如最近青睐的温暖暗物质。
Measurements of the redshift-space galaxy clustering have been a prolific source of cosmological information in recent years. Accurate covariance estimates are an essential step for the validation of galaxy clustering models of the redshift-space two-point statistics. Usually, only a limited set of accurate N-body simulations is available. Thus, assessing the data covariance is not possible or only leads to a noisy estimate. Further, relying on simulated realisations of the survey data means that tests of the cosmology dependence of the covariance are expensive. With these points in mind, this…
A systematic study of projection biases in the Weak Lensing analysis of cosmic shear and the combination of galaxy clustering and galaxy-galaxy lensing
We present a novel simulation-based cosmological analysis of galaxy-galaxy lensing and galaxy redshift-space clustering. Compared to analysis methods based on perturbation theory, our simulation-based approach allows us to probe a much wider range of scales, $0.4 \, h^{-1} \, \mathrm{Mpc}$ to $63 \, h^{-1} \, \mathrm{Mpc}$, including highly non-linear scales, and marginalises over astrophysical effects such as assembly bias. We apply this framework to data from the Baryon Oscillation Spectroscopic Survey LOWZ sample cross-correlated with state-of-the-art gravitational lensing catalogues from t…
We propose a novel method to measure the $E_G$ statistic from clustering alone. The $E_G$ statistic provides an elegant way of testing the consistency of General Relativity by comparing the geometry of the Universe, probed through gravitational lensing, with the motion of galaxies in that geometry. Current $E_G$ estimators combine galaxy clustering with gravitational lensing, measured either from cosmic shear or from CMB lensing. In this paper, we construct a novel estimator for $E_G$, using only clustering information obtained from two tracers of the large-scale structure: intensity mapping a…
We perform an ensemble of $N$-body simulations with $2048^3$ particles for 101 flat $w$CDM cosmological models sampled based on a maximin-distance Sliced Latin Hypercube Design. By using the halo catalogs extracted at multiple redshifts in the range of $z=[0,1.48]$, we develop Dark Emulator, which enables fast and accurate computations of the halo mass function, halo-matter cross-correlation, and halo auto-correlation as a function of halo masses, redshift, separations and cosmological models, based on the Principal Component Analysis and the Gaussian Process Regression for the large-dimension…
We determine the error introduced in a joint halo model analysis of galaxy-galaxy lensing and galaxy clustering observables when adopting the standard approximation of linear halo bias. Considering the Kilo-Degree Survey, we forecast that ignoring the non-linear halo bias would result in up to 5$σ$ offsets in the recovered cosmological parameters describing structure growth, $S_8$, and the matter density parameter, $Ω_{\mathrm{m}}$. We include the scales $10^{-1.3}<r_{\rm{p}} \ / h^{-1}\, \mathrm{Mpc}<10$ in the data vector, and the direction of these offsets are shown to depend on the freedom…
Observations of galaxy clustering are made in redshift space, which results in distortions to the underlying isotropic distribution of galaxies. These redshift-space distortions (RSD) not only degrade important features of the matter density field, such as the baryonic acoustic oscillation (BAO) peaks, but also pose challenges for the theoretical modelling of observational probes. Here we introduce an iterative nonlinear reconstruction algorithm to remove RSD effects from galaxy clustering measurements, and assess its performance by using mock galaxy catalogues. The new method is found to be a…
A typical galaxy survey geometry results in galaxy pairs of different separation and angle to the line-of-sight having different distributions in redshift and consequently a different effective redshift. However, clustering measurements are analysed assuming that the clustering is representative of that at a single effective redshift. We investigate the impact of variations in the galaxy-pair effective redshift on the large-scale clustering measured in galaxy surveys. We find that galaxy surveys spanning a large redshift range have different effective redshifts as a function of both pair separ…
Small- and intermediate-scale galaxy clustering can be used to establish the galaxy-halo connection to study galaxy formation and evolution and to tighten constraints on cosmological parameters. With the increasing precision of galaxy clustering measurements from ongoing and forthcoming large galaxy surveys, accurate models are required to interpret the data and extract relevant information. We introduce a method based on high-resolution N-body simulations to accurately and efficiently model the galaxy two-point correlation functions (2PCFs) in projected and redshift spaces. The basic idea is …
We present a study on the robustness of the covariance matrix estimation for galaxy clustering measurements depending on the cosmological parameters and galaxy bias. To this end, we have produced 9000 galaxy mock catalogues relying on the effective Zel'dovich approximation implemented in the EZmocks computer code, using different input cosmological models and bias parameters. The reference catalogue has also been produced with this code making our study insensitive to the approximation at least on a relative-qualitative level. Our findings indicate that the covariance matrix is insensitive to …
In the context of next-generation spectroscopic galaxy surveys, new statistics of the distribution of matter are currently being developed. Among these, we investigated the angular redshift fluctuations (ARF), which probe the information contained in the projected redshift distribution of galaxies. Relying on the Fisher formalism, we show how ARF will provide complementary cosmological information compared to traditional angular galaxy clustering. We tested both the standard $\mathrm{ΛCDM}$ model and the $\mathrm{wCDM}$ extension. We find that the cosmological and galaxy bias parameters expres…
Clustering of dark matter halos has been shown to depend on halo properties beyond mass such as halo concentration, a phenomenon referred to as halo assembly bias. Standard halo occupation models (HOD) in large scale structure studies assume that halo mass alone is sufficient in characterizing the connection between galaxies and halos. Modeling of galaxy clustering can face systematic effects if the number of galaxies within a halo is correlated with other halo properties. Using the Small MultiDark-Planck high resolution $N$-body simulation and the clustering measurements of the Sloan Digital …
We study the impact of neglecting lensing magnification in galaxy clustering analyses for future galaxy surveys, considering the LambdaCDM model and two extensions: massive neutrinos and modifications of General Relativity. Our study focuses on the biases on the constraints and on the estimation of the cosmological parameters. We perform a comprehensive investigation of these two effects for the upcoming photometric and spectroscopic galaxy surveys Euclid and SKA for different redshift binning configurations. We also provide a fitting formula for the magnification bias of SKA. Our results show…
We investigate the expected cosmological constraints from a combination of weak lensing and large-scale galaxy clustering using realistic redshift distributions. Introducing a systematic bias in the weak lensing redshift distributions (of 0.05 in redshift) produces a $>2σ$ bias in the recovered matter power spectrum amplitude and dark energy equation of state, for preliminary Stage III surveys. We demonstrate that these cosmological errors can be largely removed by marginalising over unknown biases in the assumed weak lensing redshift distributions, if we assume high quality redshift informati…
Photometric surveys produce large-area maps of the galaxy distribution, but with less accurate redshift information than is obtained from spectroscopic methods. Modern photometric redshift (photo-z) algorithms use galaxy magnitudes, or colors, that are obtained through multi-band imaging to produce a probability density function (PDF) for each galaxy in the map. We used simulated data to study the effect of using different photo-z estimators to assign galaxies to redshift bins in order to compare their effects on angular clustering and galaxy bias measurements. We found that if we use the enti…
Joint analysis of small-scale galaxy clustering and galaxy--galaxy lensing from BOSS galaxies
Shanghai Jiao Tong University（上海交通大学）；Shanghai Key Laboratory for Particle Physics and Cosmology（上海粒子物理与宇宙学重点实验室）；University of Waterloo（滑铁卢大学）；Waterloo Center for Astrophysics（滑铁卢天体物理学中心）；New York University（纽约大学）；Center for Cosmology and Particle Physics, Department of Physics, New York University（纽约大学物理系宇宙学与粒子物理中心）；Indian Institute of Science Education and Research（印度科学教育研究所）；Fermi National Accelerator Laboratory（费米国家加速器实验室）
Cosmological constraints from galaxy clustering and galaxy-galaxy lensing with extended SubHalo Abundance Matching
Donostia International Physics Center（圣塞巴斯蒂安国际物理中心）；Department of Physics, University of Oxford（牛津大学物理系）；Facultad de Física. Universidad de Sevilla. Multidisciplinary Unit for Energy Science（塞维利亚大学物理学院能源科学多学科单元）；IKERBASQUE, Basque Foundation for Science（伊克尔巴斯科，巴斯克科学基金会）；Institute for Theoretical Physics, Utrecht University（乌得勒支大学理论物理研究所）；Institut de Física d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology（高等物理研究所（IFAE），巴塞罗那科学与技术研究院）；Ruhr University Bochum, Faculty of Physics and Astronomy, Astronomical Institute (AIRUB), German Centre for Cosmological Lensing（波鸿鲁尔大学物理与天文学学院天文研究所（AIRUB），德国宇宙学透镜研究中心）
The combination of galaxy-galaxy lensing (GGL) and galaxy clustering is a powerful probe of low redshift matter clustering, especially if it is extended to the non-linear regime. To this end, we extend the N-body and halo occupation distribution (HOD) emulator method of arxiv:1907.06293 to model the redMaGiC sample of colour-selected passive galaxies in the Dark Energy Survey (DES), adding parameters that describe central galaxy incompleteness, galaxy assembly bias, and a scale-independent multiplicative lensing bias $A_{lens}$. We use this emulator to forecast cosmological constraints attaina…
Multiple observations made by several different telescopes have shown asymmetry between the number of spiral galaxies rotating in opposite directions in different parts of the sky. One of the immediate questions regarding the possible asymmetry of the spin directions is whether the distribution forms a cosmological-scale axis. This paper analyzes and compares 10 different datasets published in the past decade, collected by SDSS, Pan-STARRS, and Hubble Space Telescope. The datasets contain spiral galaxies separated by their spin direction, and the distribution can show dipole axes. The analysis…
We present a realistic 2000 deg$^{2}$ H$α$ galaxy mock catalog with $1<z<2$ for the Nancy Grace Roman Space Telescope galaxy redshift survey, the High Latitude Spectroscopic Survey (HLSS), created using Galacticus, a semi-analytical galaxy formation model, and high resolution cosmological N-body simulations. Galaxy clustering can probe dark energy and test gravity via baryon acoustic oscillation (BAO) and redshift space distortion (RSD) measurements. Using our realistic mock as the simulated Roman HLSS data, and a covariance matrix computed using a large set of approximate mocks created using …
The Brans-Dicke (BD) theory is the simplest Scalar-Tensor theory of gravity, which can be considered as a candidate of modified Einstein's theory of general relativity. In this work, we forecast the constraints on BD theory in the CSST galaxy clustering spectroscopic survey with a magnitude limit $\sim 23$ AB mag for point-source 5$σ$ detection. We generate mock data based on the zCOSMOS catalog and consider the observational and instrumental effects of the CSST spectroscopic survey. We predicate galaxy power spectra in the BD theory from $z=0$ to 1.5, and the galaxy bias and other systematica…
Stanford University（斯坦福大学）；Kavli Institute for Particle Astrophysics and Cosmology, Stanford University（斯坦福大学卡弗里粒子天体物理与宇宙学研究所）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；Boston University（波士顿大学）；Università degli Studi di Milano（米兰大学）；INAF-Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；University College London（伦敦大学学院）；Universidad Nacional Autónoma de México（墨西哥国立自治大学）；NSF NOIRLab（美国国家光学红外天文研究实验室）；University of Toronto（多伦多大学）
We investigate the inclusion of clustering maps in a weak lensing Minkowski functional (MF) analysis of DES-like and LSST-like simulations to constrain cosmological parameters. The standard 3x2pt approach to lensing and clustering data uses two-point correlations as its primary statistic; MFs, morphological statistics describing the shape of matter fields, provide additional information for non-Gaussian fields. Previous analyses have studied MFs of lensing convergence maps; in this project we explore their simultaneous application to clustering maps. We employ a simplified linear galaxy bias m…
Using dark matter simulations we show how halo bias is determined by local density and not by halo mass. This is not totally surprising, as according to the peak-background split model, local density is the property that constraints bias at large scales. Massive haloes have a high clustering because they reside in high density regions. Small haloes can be found in a wide range of environments which determine their clustering amplitudes differently. This contradicts the assumption of standard Halo Occupation Distribution (HOD) models that the bias and occupation of haloes is determined solely b…
We explore the clustering of galaxy groups in the Galaxy and Mass Assembly (GAMA) survey to investigate the dependence of group bias and profile on separation scale and group mass. Due to the inherent uncertainty in estimating the group selection function, and hence the group auto-correlation function, we instead measure the projected galaxy--group cross-correlation function. We find that the group profile has a strong dependence on scale and group mass on scales $r_\bot \lesssim 1 h^{-1} \mathrm{Mpc}$. We also find evidence that the most massive groups live in extended, overdense, structures.…
Probing dipolar power asymmetry with galaxy clustering and intrinsic alignments
Kyoto University（京都大学）；Yukawa Institute for Theoretical Physics, Kyoto University（京都大学汤川理论物理研究所）；Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo（东京大学宇宙物理数学卡弗里研究所（WPI））；Korea Institute for Advanced Study（韩国高等科学技术院）；Academia Sinica Institute of Astronomy and Astrophysics (ASIAA)（中央研究院天文及天文物理研究所）；Onomichi City University（尾道市立大学）；Suwa University of Science（诹访科学大学）
We study the clustering dependence of X-ray AGN and normal galaxies on the stellar mass (M$_\star$), star-formation rate (SFR) and specific star-formation rate (sSFR) of the (host) galaxy. Towards this end, we use 407 X-ray AGN from the XMM-XXL survey ($\sim$ 25 deg$^2$ in the North) and $\sim45,000$ galaxies in the VIPERS field (W1: $\sim$16 deg$^2$). We match the AGN and galaxy samples to have the same M$_\star$, SFR and redshift distributions. Based on our results, the two populations live in DMHs with similar mass ($\log M / (M_{\odot} \, h^{-1})\approx 12.8$) and have similar dependence o…
Statistical studies of galaxy-galaxy interactions often utilise net change in physical properties of progenitors as a function of the separation between their nuclei to trace both the strength and the observable timescale of their interaction. In this study, we use two-point auto, cross and mark correlation functions to investigate the extent to which small-scale clustering properties of star forming galaxies can be used to gain physical insight into galaxy-galaxy interactions between galaxies of similar optical brightness and stellar mass. The Halpha star formers, drawn from the highly spatia…
Galaxies exhibit different clustering and quenching properties in clusters, filaments, and the field, but it is still uncertain whether such differences are imprints of the tidal environment on galaxy formation, or if they reflect the variation of the underlying halo mass function across the cosmic web. We measure the dependence of galaxy clustering and quenching on the cosmic web in the Sloan Digital Sky Survey, characterized by the combination of spherical overdensity $δ_8$ and tidal anisotropy $α_5$ centred on each galaxy. We find that galaxy clustering is a strong function of either $δ_8$ …
Understanding the impact of halo properties beyond halo mass on the clustering of galaxies (namely galaxy assembly bias) remains a challenge for contemporary models of galaxy clustering. We explore the use of machine learning to predict the halo occupations and recover galaxy clustering and assembly bias in a semi-analytic galaxy formation model. For stellar-mass selected samples, we train a Random Forest algorithm on the number of central and satellite galaxies in each dark matter halo. With the predicted occupations, we create mock galaxy catalogues and measure the clustering and assembly bi…
