Unveiling galaxy pair alignment in cosmic filaments: A 3D exploration using EAGLE simulation
Suman Sarkar, Biswajit Pandey
备注：
17 pages, 1 table, 6 figures, updated results presented after correcting a bug in a code that significantly affected our results presented in the earlier version. Accepted in JCAP
We investigate how galaxy pairs are oriented in three dimensions within cosmic filaments using data from the EAGLE simulation. We identify filament spines using DisPerSE and isolate galaxies residing in filamentary environments. Employing a FoF algorithm, we delineate individual filaments and determine their axes by diagonalizing the moment of inertia tensor. The orientations of galaxy pairs relative to the axis of their host filament are analyzed. Our study covers diverse subsets of filaments identified through varying linking lengths, examining how galaxy pairs align with the filament axis across different spatial parameters such as pair separation and distance from the filament spine. We observe a nearly uniform probability distribution for the cosine of the orientation angle, which is nearly identical in each case. We also investigate the effects of redshift space distortions and confirm that the probability distributions remain uniform in both real space and redshift space. To validate our approach, we conduct Monte Carlo simulations using various theoretical probability distributions. Our analysis does not reveal any evidence of preferential alignment of galaxy pairs within cosmic filaments in hydrodynamical simulations.
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…
Context. A significant fraction of the predicted baryons remains undetected in the local universe. We adopted the common assumption that a large fraction of the missing baryons corresponds to the hot (log T(K) = 5.5-7) phase of the Warm Hot Intergalactic Medium (WHIM). We base our missing baryons search on the scenario whereby the WHIM has been heated up via accretion shocks and galactic outflows, and is concentrated towards the filaments of the Cosmic Web. Aims. Our aim is to improve the observational search of the poorly detected hot WHIM. Methods. We detect the filamentary structure within …
The current observational status of the hot (log T(K) > 5.5) warm-hot intergalactic medium (WHIM) remains incomplete. While recent observations from stacking large numbers of Cosmic Web filaments have yielded statistically significant detections, direct measurements of single objects remain scarce. The lack of such a sample currently prevents a robust analysis of the cosmic baryon content composed of the hot WHIM, which could help solve the cosmological missing baryons problem. To improve the search for the missing baryons, we used the EAGLE simulation. Our aim is to understand the metal enric…
A substantial fraction of the cosmic baryons is expected to hide in the form of diffuse warm-hot intergalactic medium (WHIM), the majority of which resides in the filaments of the Cosmic Web and has proven very difficult to detect due to its low density. Close to galaxy clusters, the filament gas is affected by the cluster's gravitational potential and attains substantial infall velocities, eventually undergoing a termination shock which may boost its X-ray signal. We aim to identify the optimal locations of the enhanced X-ray emission and absorption arising from cluster-filament interactions,…
This paper presents an updated scaling relation between the optical luminosity density (LD) of galaxies in the $r$ band and the density of the warm-hot intergalactic medium (WHIM) in cosmic filaments, using the high-resolution EAGLE simulations. We find a strong degree of correlation between the WHIM density and the galaxy luminosity density, resulting in a scaling relation between the two quantities that permits to predict the WHIM density of filaments with a scatter of less than $\frac{1}{2}$ dex in a broad range of smoothed filament luminosity densities. In order to estimate the performance…
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）
We use the EAGLE cosmological, hydrodynamical simulations to predict the column density and equivalent width distributions of intergalactic O VII ($E=574$ eV) and O VIII ($E=654$ eV) absorbers at low redshift. These two ions are predicted to account for 40% of the gas-phase oxygen, which implies that they are key tracers of cosmic metals. We find that their column density distributions evolve little at observable column densities from redshift 1 to 0, and that they are sensitive to AGN feedback, which strongly reduces the number of strong (column density $N \gtrsim 10^{16} \, \mathrm{cm}^{-2})…
Detection of HI filament: Pair Stacking vs. Filament Stacking
National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文学与空间科学学院）
Anisotropy of Satellite Galaxies-I: Contrasting Correlations with Central Galaxy, Host Halo, and Large-Scale Filament Structures
National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；College of Astronomy and Space Sciences, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；Universidad Autónoma de Madrid（马德里自治大学）；Centro de Investigación Avanzada en Física Fundamental (CIAFF), Universidad Autónoma de Madrid（马德里自治大学基础物理前沿研究中心）；Institute for Astronomy, University of Edinburgh（爱丁堡大学天体物理研究所）；Department of Physics and Astronomy, University of the Western Cape（西开普大学物理与天文学系）；Observatoire Astronomique de Strasbourg, UMR 7550, CNRS, Université de Strasbourg（斯特拉斯堡天文台）
Unveiling the intergalactic magnetic field (IGMF) in filaments of galaxies is a very important and challenging subject in modern astronomy. In order to probe the IGMF from rotation measures (RMs) of extragalactic radio sources, we need to separate RMs due to other origins such as the source, intervening galaxies, and our Galaxy. In this paper, we discuss observational strategies for the separation by means of Faraday tomography (Faraday RM Synthesis). We consider an observation of a single radio source such as a radio galaxy or a quasar viewed through the Galaxy and the cosmic web. We then com…
In the context of the BUFFALO (Beyond Ultra-deep Frontier Fields And Legacy Observations) survey, we present a new analysis of the merging galaxy cluster MACS\,J0416.1-2403 ($z = 0.397$) and its parallel field using the data collected by the Hubble Frontier Fields (HFF) campaign. In this work, we measure the surface mass density from a weak-lensing analysis, and characterise the overall matter distribution in both the cluster and parallel fields. The surface mass distribution derived for the parallel field shows clumpy overdensities connected by filament-like structures elongated in the direct…
We present a cosmological hydrodynamical simulation of a 10^13 Msun galaxy group and its environment (out to 10 times the virial radius) carried out using the EAGLE model of galaxy formation. Exploiting a novel technique to increase the resolution of the dark matter calculation independently of that of the gas, the simulation resolves dark matter haloes and subhaloes of mass 5x10^6 Msun . It is therefore useful for studying the abundance and properties of the haloes and subhaloes targeted in strong lensing tests of the cold dark matter model. We estimate the halo and subhalo mass functions and…
