The standard cosmological model ($Λ$CDM) predicts the existence of the cosmic web: a distribution of matter into sheets and filaments connecting massive halos. However, observational evidence has been elusive due to the low surface brightness of the filaments. Recent deep MUSE/VLT data and upcoming observations offer a promising avenue for Ly$α$ detection, motivating the development of modern theoretical predictions. We use hydrodynamical cosmological simulations run with the AREPO code to investigate the potential detectability of large-scale filaments, excluding contributions from the halos embedded in them. We focus on filaments connecting massive ($M_{200c}\sim(1-3)\times10^{12} M_\odot$) halos at z=3, and compare different simulation resolutions, feedback levels, and mock-image pixel sizes. We find increasing simulation resolution does not substantially improve detectability notwithstanding the intrinsic enhancement of internal filament structure. By contrast, for a MUSE integration of 31 hours, including feedback increases the detectable area by a factor of $\simeq$5.5 on average compared with simulations without feedback, implying that even the non-bound components of the filaments have substantial sensitivity to feedback. Degrading the image resolution from the native MUSE scale of (0.2")$^2$ per pixel to (5.3")$^2$ apertures has the strongest effect, increasing the detectable area by a median factor of $\simeq$200 and is most effective when the size of the pixel roughly matches the width of the filament. Finally, we find the majority of Ly$α$ emission is due to electron impact collisional excitations, as opposed to radiative recombination.
The weak lensing of cosmic web filaments is investigated in modified gravity (MOG) and it is demonstrated that the detected galaxies and baryonic gas of order $5-15 \%$ in filaments can with the enhanced value of the strength of gravity agree with the lensing data for filaments without dark matter.
The nature versus nurture scenario in galaxy and group evolution is a long-standing problem not yet fully understood on cosmological scales. We study the properties of groups and their central galaxies in different large-scale environments defined by the luminosity density field and the cosmic web filaments. We use the luminosity density field constructed using 8 Mpc/h smoothing to characterize the large-scale environments and the Bisous model to extract the filamentary structures in different large-scale environments. We find differences in the properties of central galaxies and their groups …
We investigate the spin evolution of dark matter haloes and their dependence on the number of connected filaments from the cosmic web at high redshift (spin-filament relation hereafter). To this purpose, we have simulated $5000$ haloes in the mass range $5\times10^{9}h^{-1}M_{\odot}$ to $5\times10^{11}h^{-1}M_{\odot}$ at $z=3$ in cosmological N-body simulations. We confirm the relation found by Prieto et al. 2015 where haloes with fewer filaments have larger spin. We also found that this relation is more significant for higher halo masses, and for haloes with a passive (no major mergers) assem…
We explore the evolution of halo spins in the cosmic web using a very large sample of dark matter haloes in the $Λ$CDM Planck-Millennium N-body simulation. We use the NEXUS+ multiscale formalism to identify the hierarchy of filaments and sheets of the cosmic web at several redshifts. We find that at all times the magnitude of halo spins correlates with the web environment, being largest in filaments, and, for the first time, we show that it also correlates with filament thickness as well as the angle between spin-orientation and the spine of the host filament. For example, massive haloes in th…
We investigate whether the satellite luminosity function (LF) of primary galaxies identified in the Sloan Digital Sky Survey (SDSS) depends on whether the host galaxy is in a filament or not. Isolated primary galaxies are identified in the SDSS spectroscopic sample while potential satellites (that are up to 4 magnitudes fainter than their hosts) are searched for in the much deeper photometric sample. Filaments are constructed from the galaxy distribution by the "Bisous" process. Isolated primary galaxies are divided into two subsamples: those in filaments and those not in filaments. We examine…
The intergalactic medium (IGM) plays an important role in the formation and evolution of galaxies. Recent developments in upcoming radio telescopes are starting to open up the possibility of making a first direct detection of the 21 cm signal of neutral hydrogen (HI) from the warm gas of the IGM in large-scale filaments. The cosmological hydrodynamical EAGLE simulation is used to estimate the typical IGM filament signal. Assuming the same average signal for all filaments, a prediction is made for the detectability of such a signal with the upcoming mid-frequency array of the Square Kilometer A…
Cosmological simulations predict the Universe contains a network of intergalactic gas filaments, within which galaxies form and evolve. However, the faintness of any emission from these filaments has limited tests of this prediction. We report the detection of rest-frame ultraviolet Lyman-alpha radiation from multiple filaments extending more than one megaparsec between galaxies within the SSA 22 proto-cluster at a redshift of 3.1. Intense star formation and supermassive black-hole activity is occurring within the galaxies embedded in these structures, which are the likely sources of the eleva…
We investigate the alignment of haloes with the filaments of the cosmic web using an unprecedently large sample of dark matter haloes taken from the P-Millennium $Λ$CDM cosmological N-body simulation. We use the state-of-the-art NEXUS morphological formalism which, due to its multiscale nature, simultaneously identifies structures at all scales. We find strong and highly significant alignments, with both the major axis of haloes and their peculiar velocity tending to orient along the filament. However, the spin - filament alignment displays a more complex trend changing from preferentially par…
Next-generation wide-field spectroscopic surveys will observe the infall regions around large numbers of galaxy clusters with high sampling rates for the first time. Here we assess the feasibility of extracting the large-scale cosmic web around clusters using forthcoming observations, given realistic observational constraints. We use a sample of 324 hydrodynamic zoom-in simulations of massive galaxy clusters from TheThreeHundred project to create a mock-observational catalogue spanning $5R_{200}$ around 160 analogue clusters. These analogues are matched in mass to the 16 clusters targetted by …
The Cosmic Web is a complex network of filaments, walls and voids that represent the largest structures in the Universe. In this network, which is the direct result of structure formation, galaxy clusters occupy central positions as the nodes, connected through the filaments. In this work, we investigate the position in the Cosmic Web of one of the most known and best studied clusters of galaxies, the Coma cluster. We make use of the Sloan Digital Sky Survey Data Release 7 (SDSS DR7) Main Galaxy Sample and of the Discrete Persistent Structure Extractor (DisPerSE) to detect large scale filament…
The cold dark matter model predicts that dark matter haloes are connected by filaments. Direct measurements of the masses and structure of these filaments are difficult, but recently several studies have detected these dark-matter-dominated filaments using weak lensing. Here we study the efficiency of galaxy formation within the filaments by measuring their total mass-to-light ratios and stellar mass fractions. Specifically, we stack pairs of Luminous Red Galaxies (LRGs) with a typical separation on the sky of $8 h^{-1}$ Mpc. We stack background galaxy shapes around pairs to obtain mass maps t…
In the current cosmological paradigm, an initially flat three-dimensional manifold that pervades space (the `dark-matter sheet') folds up to build concentrations of mass (galaxies), and a cosmic web between them. Galaxies are nodes, connected by a network of filaments and walls. The folding is in six-dimensional (3D position, plus 3D velocity) phase space. The positions of creases, or caustics, mark the edges of structures. Here, I introduce an origami approximation to cosmological structure formation, in which the dark-matter sheet is not allowed to stretch. But it still produces an idealized…
We used the Rotation Measure (RM) catalogue derived from the LOFAR Two-metre Sky Survey Data Release 2 (LoTSS DR2) at 144-MHz to measure the evolution with redshift of the extragalactic RM (RRM: Residual RM) and the polarization fraction ($p$) of sources in low density environments. We also measured the same at 1.4-GHz by cross-matching with the NRAO VLA Sky Survey RM catalogue. We find that RRM versus redshift is flat at 144-MHz, but, once redshift-corrected, it shows evolution at high significance. Also $p$ evolves with redshift with a decrement by a factor of $\sim$8 at $z\sim2$. Comparing …
Tracing Galaxy Bias Through the Cosmic Web: The Role of Filaments
Universidad Técnica Federico Santa María(弗雷德里克·Santa Maria 技术大学);Pontificia Universidad Católica de Valparaíso(瓦爾帕萊索天主教大學);The University of Tokyo(東京大學);University of Pennsylvania(賓夕法尼亞大學);The Abdus Salam International Center for Theoretical Physics(阿卜杜斯·薩拉姆國際理論物理中心);Universidad Nacional de Córdoba(科爾多瓦國立大學);CONICET-UNC(阿根廷國家科學技術研究委員會-科爾多瓦大學)
Filaments and clusters of the cosmic web have an impact on the properties of galaxies, switching off their star-formation, contributing to the build-up of their stellar mass, and influencing the acquisition of their angular momentum. In this work we make use of the IllustrisTNG simulation, coupled with the DisPerSE cosmic web extraction algorithm, to test which is the galaxy property most affected by the cosmic web and, conversely, to assess the differential impact of the various cosmic web features on a given galaxy property. Our aim is to use this information to better understand galaxy evol…
Filaments of the cosmic web drive spin acquisition of disc galaxies. The point process of filament-type saddle represent best this environment and can be used to revisit the Tidal Torque Theory in the context of an anisotropic peak (saddle) background split. The constrained misalignment between the tidal tensor and the Hessian of the density field generated in the vicinity of filament saddle points simply explains the corresponding transverse and longitudinal point-reflection symmetric geometry of spin distribution. It predicts in particular an azimuthal orientation of the spins of more massiv…
Star-forming galaxies in the cosmic web in the last 11 Gyr
Observatoire Astronomique de Strasbourg, UMR 7550, CNRS, Université de Strasbourg(斯特拉斯堡天文台);Institute for Astronomy, University of Edinburgh(爱丁堡大学天体物理研究所);Department of Physics and Astronomy, University of the Western Cape(西开普大学物理与天文学系)
We present a new method of tracking and characterizing the environment in which galaxies and their associated circumgalactic medium evolve. We use a structure finding algorithm we developed to self-consistently parse and follow the evolution of poor clusters, filaments and voids in large scale simulations. We trace the complete evolution of the baryons in the gas phase and the star formation history within each structure in our simulated volume. We vary the structure measure threshold to probe the complex inner structure of star forming regions in poor clusters, filaments and voids. We find th…
We study the effects of filaments on galaxy properties in the Sloan Digital Sky Survey (SDSS) Data Release 12 using filaments from the `Cosmic Web Reconstruction' catalogue (Chen et al. 2016), a publicly available filament catalogue for SDSS. Since filaments are tracers of medium-to-high density regions, we expect that galaxy properties associated with the environment are dependent on the distance to the nearest filament. Our analysis demonstrates that a red galaxy or a high-mass galaxy tend to reside closer to filaments than a blue or low-mass galaxy. After adjusting the effect from stellar m…
Context. The cosmic web, a complex network of galaxy groups and clusters connected by filaments, is a dynamical environment in which galaxies form and evolve. However, the impact of cosmic filaments on the properties of galaxies is difficult to study because of the much more influential local (galaxy-group scale) environment. Aims. The aim of this paper is to investigate the dependence of intrinsic galaxy properties on distance to the nearest cosmic web filament, using a sample of galaxies for which the local environment is easily assessable.} Methods. Our study is based on a volume-limited ga…
Impact of Cosmic Filaments on Galaxy Morphological Evolution and Predictions of Early Cosmic Web Structure for Roman
Space Telescope Science Institute(太空望远镜科学研究所);New Mexico State University(新墨西哥州立大学);Steward Observatory, University of Arizona(亚利桑那大学斯图尔德天文台);Canadian Institute for Theoretical Astrophysics, University of Toronto(多伦多大学加拿大理论天体物理研究所);Columbia Astrophysics Laboratory, Columbia University(哥伦比亚大学哥伦比亚天体物理学实验室);Johns Hopkins University(约翰斯·霍普金斯大学)
Observations of the cosmic microwave background indicate that baryons account for 5% of the Universe's total energy content. In the local Universe, the census of all observed baryons falls short of this estimate by a factor of two. Cosmological simulations indicate that the missing baryons might not have condensed into virialized haloes, but reside throughout the filaments of the cosmic web (where matter density is larger than average) as a low-density plasma at temperatures of $10^5-10^7$ kelvin, known as the warm-hot intergalactic medium. There have been previous claims of the detection of w…
The role of the cosmic web in shaping galaxy properties is investigated in the GAMA spectroscopic survey in the redshift range $0.03 \leq z \leq 0.25$. The stellar mass, $u - r$ dust corrected colour and specific star formation rate (sSFR) of galaxies are analysed as a function of their distances to the 3D cosmic web features, such as nodes, filaments and walls, as reconstructed by DisPerSE. Significant mass and type/colour gradients are found for the whole population, with more massive and/or passive galaxies being located closer to the filament and wall than their less massive and/or star-fo…
We present a statistical study of the filamentary structures of the cosmic web in the large hydro-dynamical simulations Illustris-TNG, Illustris, and Magneticum at redshift z=0. We focus on the radial distribution of the galaxy density around filaments detected using the Discrete Persistent Structure Extractor (DisPerSE). We show that the average profile of filaments presents an excess of galaxy density (> 5 sigma) up to radial distances of 27 Mpc from the core. The relation between galaxy density and the length of filaments is further investigated showing that short (L_f < 9 Mpc) and long (L_…
Using reconstructed initial conditions in the SDSS survey volume, we carry out constrained hydrodynamic simulations in three regions representing different types of the cosmic web: the Coma cluster of galaxies; the SDSS great wall; and a large low-density region at $z\sim 0.05$. These simulations, which include star formation and stellar feedback but no AGN formation and feedback, are used to investigate the properties and evolution of intergalactic and intra-cluster media. About half of the warm-hot intergalactic gas is associated with filaments in the local cosmic web. Gas in the outskirts o…
The Evolution of the Spin Alignments of Dark Matter Halos in the Cosmic Web
Universidad Técnica Federico Santa María(费德里科·圣玛丽亚技术大学);Millenium Nucleus for Galaxies (MINGAL)(星系千年核心(MINGAL));Observatoire Astronomique de Strasbourg, Université de Strasbourg, CNRS, UMR 7550(斯特拉斯堡天文台,斯特拉斯堡大学,法国国家科学研究中心,UMR 7550);Observatorio Astronómico de Córdoba, Universidad Nacional de Córdoba (UNC)(科尔多瓦天文台,科尔多瓦国立大学(UNC));Instituto de Astronomía Teórica y Experimental, CONICET-UNC(理论与实验天体物理研究所,阿根廷国家科学研究委员会-科尔多瓦国立大学)
In the local universe, a large fraction of the baryon content is believed to exist as diffuse gas in filaments. While this gas is directly observable in X-ray emission around clusters of galaxies, it is primarily studied through its UV absorption. Recently, X-ray observations of large-scale filaments connecting to the cosmic web around the nearby ($z=0.05584$) cluster Abell 133 were reported. One of these filaments is intersected by the sightline to quasar [VV98] J010250.2$-$220929, allowing for a first-ever census of cold, cool, and warm gas in a filament of the cosmic web where hot gas has b…
We study the spin alignment of galaxies and halos with respect to filaments and walls of the cosmic web, identified with DisPerSE, using the SIMBA simulation from z=0-2. Massive halos' spins are oriented perpendicularly to their closest filament's axis and walls, while low mass halos tend to have their spins parallel to filaments and in the plane of walls. A similar mass-dependent spin flip is found for galaxies, albeit with a weaker signal particularly at low mass and low-z, suggesting that galaxies' spins retain memory of their larger-scale environment. Low-z star-forming and rotation-domina…
The Three Hundred project: cosmic web identification from 2D gas and Compton-$y$ maps of galaxy clusters outskirts
Sapienza Università di Roma(罗马第一大学);Universidad Autónoma de Madrid(马德里自治大学);Centro de Investigación Avanzada en Física Fundamental (CIAFF)(基础物理高级研究中心);University of Edinburgh(爱丁堡大学);Universidad Rey Juan Carlos(雷乌斯·胡安·卡洛斯国王大学);Università degli Studi di Napoli Federico II(那不勒斯费德里科二世大学)
We study the 3D axis of rotation (3D spin) of 77 HI galaxies from the MIGHTEE-HI Early Science observations, and its relation to the filaments of the cosmic web. For this HI-selected sample, the alignment between the spin axis and the closest filament ($\lvert \cos ψ\rvert$) is higher for galaxies closer to the filaments, with $\langle\lvert \cos ψ\rvert\rangle= 0.66 \pm 0.04$ for galaxies $<5$ Mpc from their closest filament compared to $\langle\lvert \cos ψ\rvert\rangle= 0.37 \pm 0.08$ for galaxies at $5 < d <10$ Mpc. We find that galaxies with a low HI-to-stellar mass ratio ($\log_{10}(M_{\…
Zippers and Twisters: Planes of Satellite Galaxies Emerge from Whirling and Shocking Gas Streams in the Cosmic Web
Johns Hopkins University(约翰斯·霍普金斯大学);NYC College of Technology, City University of New York(纽约市立大学学院技术学院);Graduate Center, City University of New York(纽约市立大学研究生中心);Institut d’Astrophsyique de Paris, UMR 7095, CNRS, UPMC Univ.(巴黎天体物理研究所);Kyung Hee University(庆熙大学);LSST-DA Catalyst Fellowship, LSST Discovery Alliance(LSST-DA催化剂奖学金,LSST发现联盟);Centre for Astrophysics Research, University of Hertfordshire(赫特福德大学天体物理学研究中心)
Mapping the intergalactic medium (IGM) in Lyman-$α$ emission would yield unprecedented tomographic information on the large-scale distribution of baryons and potentially provide new constraints on the UV background and various feedback processes relevant to galaxy formation. Here, we use a cosmological hydrodynamical simulation to examine the Lyman-$α$ emission of the IGM due to collisional excitations and recombinations in the presence of a UV background. We focus on gas in large-scale-structure filaments in which Lyman-$α$ radiative transfer effects are expected to be moderate. At low densit…
We explore the characteristics of the cosmic web around Local Group(LG) like pairs using a cosmological simulation in the $Λ$CDM cosmology. We use the Hessian of the gravitational potential to classify regions on scales of $\sim 2$ Mpc as a peak, sheet, filament or void. The sample of LG counterparts is represented by two samples of halo pairs. The first is a general sample composed by pairs with similar masses and isolation criteria as observed for the LG. The second is a subset with additional observed kinematic constraints such as relative pair velocity and separation. We find that the pair…
Unveiling the small-scale web around galaxies with miniJPAS and DESI
Max-Planck Institute for Astrophysics(马克斯·普朗克天体物理学研究所);Kavli IPMU (WPI), UTIAS, The University of Tokyo(理化学研究所木下原宇宙起源研究核心理论中心( Kavli IPMU)、东京大学宇宙射线研究所、东京大学);Donostia International Physics Center (DIPC)(圣塞巴斯蒂安国际物理中心);IKERBASQUE, Basque Foundation for Science(伊克尔巴斯基克科学基金会);Hamburger Sternwarte, Universität Hamburg(汉堡天文台,汉堡大学);Instituto de Astrofísica de Andalucía (IAA-CSIC)(安达卢西亚天体物理学研究所);Tartu Observatory, University of Tartu(塔尔图天文台,塔尔图大学);Estonian Academy of Sciences(爱沙尼亚科学院);Departamento de Física Matemática, Instituto de Física, Universidade de São Paulo(圣保罗大学数学物理系、物理研究所);Observatori Astronòmic de la Universitat de València(瓦伦西亚大学天文台);Departament d’Astronomia i Astrofísica, Universitat de València(瓦伦西亚大学天文学与天体物理学系);Departamento de Física, Universidade Federal do Espírito Santo(圣埃斯皮里图联邦大学物理系)
The impact of cosmic filaments on starburst galaxies across cosmic times
Observatoire Astronomique de Strasbourg, UMR 7550, CNRS, Université de Strasbourg(斯特拉斯堡天文台,法国国家科学研究中心,斯特拉斯堡大学);Institut d’Astrophysique de Paris, UMR 7095, CNRS, Sorbonne Université(巴黎天体物理研究所,法国国家科学研究中心,索邦大学);SRON Netherlands Institute for Space Research(荷兰空间研究所);Kapteyn Astronomical Institute, University of Groningen(格罗宁根大学卡普坦天文研究所);European Space Agency/ESTEC(欧洲空间局/欧洲空间研究与技术中心);Leiden Observatory, Leiden University(莱顿大学莱顿天文台);Aix Marseille Univ, CNRS, CNES, LAM(艾克斯-马赛大学,法国国家科学研究中心,法国国家太空研究中心);The University of Texas at Austin(德克萨斯大学奥斯汀分校);Department of Physics, University of California, Santa Barbara(加州大学圣塔芭芭拉分校物理系);Cosmic Dawn Center (DAWN)(宇宙黎明中心);Institute for Computational Cosmology, Department of Physics, Durham University(杜伦大学物理系计算宇宙学研究所)
We investigate the alignment of galaxies and haloes relative to cosmic web filaments using the EAGLE hydrodynamical simulation. We identify filaments by applying the NEXUS+ method to the mass distribution and the Bisous formalism to the galaxy distribution. Both web finders return similar filamentary structures that are well aligned and that contain comparable galaxy populations. EAGLE haloes have an identical spin alignment with filaments as their counterparts in dark matter only simulations: a complex mass dependent trend with low mass haloes spinning preferentially parallel to and high mass…
By linking galaxies in Sloan Digital Sky Survey (SDSS) to subhaloes in the ELUCID simulation, we investigate the relation between subhalo formation time and the galaxy properties, and the dependence of galaxy properties on the cosmic web environment. We find that central and satellite subhaloes have different formation time, where satellite subhaloes are older than central subhaloes at fixed mass. At fixed mass, the galaxy stellar-to-subhalo mass ratio is a good proxy of the subhalo formation time, and increases with the subhalo formation redshifts, especially for massive galaxies. The subhalo…
Cosmic-web quenching with DESI DR1: T-Web environments and mass-dependent red/blue classification
Escuela de Física y Matemáticas del Instituto Politécnico Nacional(国立理工学院物理与数学学院);Departamento de Física, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional(国立理工学院高级研究中心物理系);Tecnologico de Monterrey, Escuela de Ingeniería y Ciencias(蒙特雷科技大学工程与科学学院)
We present neutral hydrogen (HI) and ionized hydrogen (H$α$) observations of ten galaxies out to a redshift of 0.1. The HI observations are from the first epoch (178 hours) of the COSMOS HI Large Extragalactic Survey (CHILES). Our sample is HI biased and consists of ten late-type galaxies with HI masses that range from $1.8\times10^{7}$ M$_{\odot}$ to $1.1\times10^{10}$ M$_{\odot}$. We find that although the majority of galaxies show irregularities in the morphology and kinematics, they generally follow the scaling relations found in larger samples. We find that the HI and H$α$ velocities reac…
Caught in the web: galaxy mergers along cosmic filaments
Universidad de Concepción(康塞普西翁大学);Universidad Técnica Federico Santa María(费德里科·圣玛丽亚理工大学);Millennium Nucleus for Galaxies (MINGAL)(星系千年核心(MINGAL));Pontificia Universidad Católica de Valparaíso(瓦爾帕萊索天主教大學);Universidad de La Serena(拉塞雷納大學);Instituto de Astronomía y Ciencias Planetarias (INCT), Universidad de Atacama(阿塔卡馬大學天文與行星科學研究所(INCT))
Cosmic web stripping and starvation of low-mass filament galaxies in TNG50
INAF – Osservatorio Astronomico di Trieste(意大利国家天体物理研究所的里雅斯特天文台);IFPU – Institute for Fundamental Physics of the Universe(宇宙基础物理研究所);INAF – Osservatorio Astronomico di Padova(意大利国家天体物理研究所帕多瓦天文台);Tianjin Normal University(天津师范大学);Sydney Institute for Astronomy (SIfA), School of Physics, The University of Sydney(悉尼大学物理学院天体物理研究所);School of Physics and Astronomy, University of Birmingham(伯明翰大学物理与天文学院)
We study the effects of the local environmental density and the cosmic web environment (filaments, walls, and voids) on key properties of dark matter halos using the Bolshoi-Planck LCDM cosmological simulation. The z = 0 simulation is analysed into filaments, walls, and voids using the SpineWeb method and also the VIDE package of tools, both of which use the watershed transform. The key halo properties that we study are the specific mass accretion rate, spin parameter, concentration, prolateness, scale factor of the last major merger, and scale factor when the halo had half of its z = 0 mass. …
The role played by the large-scale structures in the galaxy evolution is not quite well understood yet. In this study, we investigate properties of galaxy in the range 0.1<z<0.3 from a value-added version of the WISExSCOS catalogue around cosmic filaments detected with DisPerSE. We have fitted a profile of galaxy over-density around cosmic filaments and found a typical radius of r_m = 7.5+-0.2 Mpc. We have measured an excess of passive galaxies near the filament's spine, higher than the excess of transitioning and active galaxies. We have also detected SFR and Mstar gradients pointing towards …
Using a set of high-resolution simulations we study the statistical correlation of dark matter halo properties with the large-scale environment. We consider halo populations split into four Cosmic Web (CW) elements: voids, walls, filaments, and nodes. For the first time we present a study of CW effects for halos covering six decades in mass: $10^{8}-10^{14}{h^{-1}{\rm M}_{\odot}}$. We find that the fraction of halos living in various web components is a strong function of mass, with the majority of $M>10^{12}{h^{-1}{\rm M}_{\odot}}$ halos living in filaments and nodes. Low mass halos are more …