Relevant bibliographies by topics / Galaxy clusters

Academic literature on the topic 'Galaxy clusters'

Author: Grafiati
Published: 4 June 2021
Last updated: 8 June 2024

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Journal articles on the topic "Galaxy clusters"

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Robertson, Andrew. "The galaxy–galaxy strong lensing cross-sections of simulated ΛCDM galaxy clusters." Monthly Notices of the Royal Astronomical Society: Letters 504, no. 1 (March 22, 2021): L7—L11. http://dx.doi.org/10.1093/mnrasl/slab028.

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ABSTRACT We investigate a recent claim that observed galaxy clusters produce an order of magnitude more galaxy–galaxy strong lensing (GGSL) than simulated clusters in a Λ cold dark matter (CDM) cosmology. We take galaxy clusters from the c-eagle hydrodynamical simulations and calculate the expected amount of GGSL for sources placed behind the clusters at different redshifts. The probability of a source lensed by one of the most massive c-eagle clusters being multiply imaged by an individual cluster member is in good agreement with that inferred for observed clusters. We show that numerically converged results for the GGSL probability require higher resolution simulations than had been used previously. On top of this, different galaxy formation models predict cluster substructures with different central densities, such that the GGSL probabilities in ΛCDM cannot yet be robustly predicted. Overall, we find that GGSL within clusters is not currently in tension with the ΛCDM cosmological model.
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Benavides, José A., Laura V. Sales, and Mario G. Abadi. "Accretion of galaxy groups into galaxy clusters." Monthly Notices of the Royal Astronomical Society 498, no. 3 (September 2, 2020): 3852–62. http://dx.doi.org/10.1093/mnras/staa2636.

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ABSTRACT We study the role of group infall in the assembly and dynamics of galaxy clusters in ΛCDM. We select 10 clusters with virial mass M200 ∼ 1014 $\rm M_\odot$ from the cosmological hydrodynamical simulation Illustris and follow their galaxies with stellar mass M⋆ ≥ 1.5 × 108 $\rm M_\odot$. A median of ${\sim}38{{\ \rm per\ cent}}$ of surviving galaxies at z = 0 is accreted as part of groups and did not infall directly from the field, albeit with significant cluster-to-cluster scatter. The evolution of these galaxy associations is quick, with observational signatures of their common origin eroding rapidly in 1–3 Gyr after infall. Substructure plays a dominant role in fostering the conditions for galaxy mergers to happen, even within the cluster environment. Integrated over time, we identify (per cluster) an average of 17 ± 9 mergers that occur in infalling galaxy associations, of which 7 ± 3 occur well within the virial radius of their cluster hosts. The number of mergers shows large dispersion from cluster to cluster, with our most massive system having 42 mergers above our mass cut-off. These mergers, which are typically gas rich for dwarfs and a combination of gas rich and gas poor for M⋆ ∼ 1011 $\rm M_\odot$, may contribute significantly within ΛCDM to the formation of specific morphologies, such as lenticulars (S0) and blue compact dwarfs in groups and clusters.
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Gal-Yam, A., D. Maoz, K. Sharon, F. Prada, P. Guhathakurta, and A. V. Filippenko. "Supernovae in Galaxy Clusters." International Astronomical Union Colloquium 192 (2005): 367–71. http://dx.doi.org/10.1017/s025292110000943x.

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SummaryWe present the results of several surveys for supernovae (SNe) in galaxy clusters. SNe discovered in deep, archival HST images were used to measure the cluster SN Ia rate to z = 1. A search for SNe in nearby (0.06 ≤ z ≤ 0.2) Abell galaxy clusters yielded 15 SNe, 12 of which were spectroscopically confirmed. Of these, 7 are cluster SNe Ia, which we will use to measure the SN Ia rate in nearby clusters. This search has also discovered the first convincing examples of intergalactic SNe. We conclude with a brief description of ongoing and future cluster SN surveys.
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Gouin, C., N. Aghanim, V. Bonjean, and M. Douspis. "Probing the azimuthal environment of galaxies around clusters." Astronomy & Astrophysics 635 (March 2020): A195. http://dx.doi.org/10.1051/0004-6361/201937218.

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Galaxy clusters are connected at their peripheries to the large-scale structures by cosmic filaments that funnel accreting material. These filamentary structures are studied to investigate both environment-driven galaxy evolution and structure formation and evolution. In the present work, we probe in a statistical manner the azimuthal distribution of galaxies around clusters as a function of the cluster-centric distance, cluster richness, and star-forming or passive galaxy activity. We performed a harmonic decomposition in large photometric galaxy catalogue around 6400 SDSS clusters with masses M > 1014 solar masses in the redshift range of 0.1 < z < 0.3. The same analysis was performed on the mock galaxy catalogue from the light cone of a Magneticum hydrodynamical simulation. We used the multipole analysis to quantify asymmetries in the 2D galaxy distribution. In the inner cluster regions at R < 2R500, we confirm that the galaxy distribution traces an ellipsoidal shape, which is more pronounced for richest clusters. In the outskirts of the clusters (R = [2 − 8]R500), filamentary patterns are detected in harmonic space with a mean angular scale mmean = 4.2 ± 0.1. Massive clusters seem to have a larger number of connected filaments than lower-mass clusters. We also find that passive galaxies appear to trace the filamentary structures around clusters better. This is the case even if the contribution of star-forming galaxies tends to increase with the cluster-centric distance, suggesting a gradient of galaxy activity in filaments around clusters.
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Yoo, Jaewon, Jongwan Ko, Cristiano G. Sabiu, Jihye Shin, Kyungwon Chun, Ho Seong Hwang, Juhan Kim, M. James Jee, Hyowon Kim, and Rory Smith. "Comparison of Spatial Distributions of Intracluster Light and Dark Matter." Astrophysical Journal Supplement Series 261, no. 2 (July 27, 2022): 28. http://dx.doi.org/10.3847/1538-4365/ac7142.

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Abstract In a galaxy cluster, the relative spatial distributions of dark matter, member galaxies, gas, and intracluster light (ICL) may connote their mutual interactions over the cluster’s evolution. However, it is a challenging problem to provide a quantitative measure for matching the shapes between two multidimensional scalar distributions. We present a novel methodology, named the weighted overlap coefficient (WOC), to quantify the similarity of two-dimensional spatial distributions. We compare the WOC with a standard method known as the modified Hausdorff distance (MHD) method. We find that our method is robust, and performs well even with the existence of multiple substructures. We apply our methodology to search for a visible component whose spatial distribution resembles that of dark matter. If such a component could be found to trace the dark-matter distribution with high fidelity for more relaxed galaxy clusters, then the similarity of the distributions could also be used as a dynamical stage estimator of the cluster. We apply the method to six galaxy clusters at different dynamical stages, simulated within a GRT simulation, which is an N-body simulation using the galaxy replacement technique. Among the various components (stellar particles, galaxies, ICL), the ICL+brightest cluster galaxy (BCG) component most faithfully traced the dark-matter distribution. Among the sample galaxy clusters, the relaxed clusters show stronger similarity in the spatial distribution of the dark matter and ICL+BCG than the dynamically young clusters, while the results of the MHD method show a weaker trend with the dynamical stages.
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Henriksen, Mark J., and Prajwal Panda. "Exploiting Machine Learning and Disequilibrium in Galaxy Clusters to Obtain a Mass Profile." Astrophysical Journal Letters 961, no. 2 (January 25, 2024): L36. http://dx.doi.org/10.3847/2041-8213/ad1ede.

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Abstract We use 3D k-means clustering to characterize galaxy substructure in the A2146 cluster of galaxies (z = 0.2343). This method objectively characterizes the cluster’s substructure using projected position and velocity data for 67 galaxies within a 2.305 Mpc circular region centered on the cluster's optical center. The optimal number of substructures is found to be four. Four distinct substructures with rms velocity typical of galaxy groups or low-mass subclusters, when compared to cosmological simulations of galaxy cluster formation, suggest that A2146 is in the early stages of formation. We utilize this disequilibrium, which is so prevalent in galaxy clusters at all redshifts, to construct a radial mass distribution. Substructures are bound but not virialized. This method is in contrast to previous kinematical analyses, which have assumed virialization, and ignored the ubiquitous clumping of galaxies. The best-fitting radial mass profile is much less centrally concentrated than the well-known Navarro–Frenk–White profile, indicating that the dark-matter-dominated mass distribution is flatter pre-equilibrium, becoming more centrally peaked in equilibrium through the merging of the substructure.
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Cohn, J. D. "Galaxy subgroups in galaxy clusters." Monthly Notices of the Royal Astronomical Society 419, no. 2 (October 21, 2011): 1017–27. http://dx.doi.org/10.1111/j.1365-2966.2011.19756.x.

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Kosiba, Matej, Maggie Lieu, Bruno Altieri, Nicolas Clerc, Lorenzo Faccioli, Sarah Kendrew, Ivan Valtchanov, et al. "Multiwavelength classification of X-ray selected galaxy cluster candidates using convolutional neural networks." Monthly Notices of the Royal Astronomical Society 496, no. 4 (June 17, 2020): 4141–53. http://dx.doi.org/10.1093/mnras/staa1723.

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ABSTRACT Galaxy clusters appear as extended sources in XMM–Newton images, but not all extended sources are clusters. So, their proper classification requires visual inspection with optical images, which is a slow process with biases that are almost impossible to model. We tackle this problem with a novel approach, using convolutional neural networks (CNNs), a state-of-the-art image classification tool, for automatic classification of galaxy cluster candidates. We train the networks on combined XMM–Newton X-ray observations with their optical counterparts from the all-sky Digitized Sky Survey. Our data set originates from the XMM CLuster Archive Super Survey (X-CLASS) survey sample of galaxy cluster candidates, selected by a specially developed pipeline, the XAmin, tailored for extended source detection and characterization. Our data set contains 1707 galaxy cluster candidates classified by experts. Additionally, we create an official Zooniverse citizen science project, The Hunt for Galaxy Clusters, to probe whether citizen volunteers could help in a challenging task of galaxy cluster visual confirmation. The project contained 1600 galaxy cluster candidates in total of which 404 overlap with the expert’s sample. The networks were trained on expert and Zooniverse data separately. The CNN test sample contains 85 spectroscopically confirmed clusters and 85 non-clusters that appear in both data sets. Our custom network achieved the best performance in the binary classification of clusters and non-clusters, acquiring accuracy of 90 per cent, averaged after 10 runs. The results of using CNNs on combined X-ray and optical data for galaxy cluster candidate classification are encouraging, and there is a lot of potential for future usage and improvements.
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Lee, Jong Chul, Ho Seong Hwang, and Hyunmi Song. "Searching for Mg ii absorbers in and around galaxy clusters." Monthly Notices of the Royal Astronomical Society 503, no. 3 (March 5, 2021): 4309–19. http://dx.doi.org/10.1093/mnras/stab637.

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ABSTRACT To study environmental effects on the circumgalactic medium (CGM), we use the samples of redMaPPer galaxy clusters, background quasars, and cluster galaxies from the Sloan Digital Sky Survey (SDSS). With ∼82 000 quasar spectra, we detect 197 Mg ii absorbers in and around the clusters. The detection rate per quasar is 2.7 ± 0.7 times higher inside the clusters than outside the clusters, indicating that Mg ii absorbers are relatively abundant in clusters. However, when considering the galaxy number density, the absorber-to-galaxy ratio is rather low inside the clusters. If we assume that Mg ii absorbers are mainly contributed by the CGM of massive star-forming galaxies, a typical halo size of cluster galaxies is smaller than that of field galaxies by 30 ± 10 per cent. This finding supports that galaxy haloes can be truncated by interaction with the host cluster.
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Kuchner, Ulrike, Roan Haggar, Alfonso Aragón-Salamanca, Frazer R. Pearce, Meghan E. Gray, Agustín Rost, Weiguang Cui, Alexander Knebe, and Gustavo Yepes. "An inventory of galaxies in cosmic filaments feeding galaxy clusters: galaxy groups, backsplash galaxies, and pristine galaxies." Monthly Notices of the Royal Astronomical Society 510, no. 1 (November 27, 2021): 581–92. http://dx.doi.org/10.1093/mnras/stab3419.

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ABSTRACT Galaxy clusters grow by accreting galaxies from the field and along filaments of the cosmic web. As galaxies are accreted they are affected by their local environment before they enter (pre-processing), and traverse the cluster potential. Observations that aim to constrain pre-processing are challenging to interpret because filaments comprise a heterogeneous range of environments including groups of galaxies embedded within them and backsplash galaxies that contain a record of their previous passage through the cluster. This motivates using modern cosmological simulations to dissect the population of galaxies found in filaments that are feeding clusters, to better understand their history, and aid the interpretation of observations. We use zoom-in simulations from The ThreeHundred project to track haloes through time and identify their environment. We establish a benchmark for galaxies in cluster infall regions that supports the reconstruction of the different modes of pre-processing. We find that up to 45 per cent of all galaxies fall into clusters via filaments (closer than 1 h−1Mpc from the filament spine). 12 per cent of these filament galaxies are long-established members of groups and between 30 and 60 per cent of filament galaxies at R200 are backsplash galaxies. This number depends on the cluster’s dynamical state and sharply drops with distance. Backsplash galaxies return to clusters after deflecting widely from their entry trajectory, especially in relaxed clusters. They do not have a preferential location with respect to filaments and cannot collapse to form filaments. The remaining pristine galaxies (∼30–60 per cent) are environmentally affected by cosmic filaments alone.
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Dissertations / Theses on the topic "Galaxy clusters"

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Bonamigo, Mario. "Triaxial galaxy clusters." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4717/document.

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Il est bien établit théoriquement et observationnellement que les amas de galaxies ne sont pas des objets sphèriques, et qu'ils sont beaucoup mieux décrits par la géométrie triaxiale. Malgré cela, les travaux sur la forme tri-dimensionnelle des amas de galaxies sont encore trés rares. L'objet de cette thèse est de contribuer à cette problématique naissante. L'originalité de ce travail est d'aborder ce sujet théoriquement et observationnellement. J'ai mesuré la forme d'amas de galaxies simulés, proposant des prédictions sur la forme des haloes de matière noire. J'ai ensuite développé un algorithme qui se propose de combiner des données en lentilles gravitationnelles et en rayons X afin de contraindre un modèle de haloe triaxial. L'algorithme est testé sur des données simulées. Finalement, je présente l'analyse en rayons X de Abell 1703, qui, combinée avec l'analyse en lentilles gravitationnelles, permettra de déterminer la forme de Abell 1703
It is well established both theoretically and observationally that galaxy clusters are not spherical objects and that they are much better approximated as triaxial objects. This thesis focusses on the three dimencional shape of galaxy clusters. The originality of my approach is to tackle the problem both theoretically and observationally. First, I have measured the shape of dark matter haloes in the Millenium XXL and Sbarbine simulations, providing predictions for dark matter halo shape over 5 order in magnitude in mass. Then, I have developed an algorithm aimed at fitting simultaneously lensing and X-ray data in order to constrain a triaxial mass distribution. The algorithm is tested and characterized on mock data sets. It is found to be able to recover the input parameters. Finally, I present the X-ray analysis of galaxy cluster Abell 1703, which will be combined with the existing lensing analysis in order to investigate its shape
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Eke, Vincent R. "Cosmology with galaxy clusters." Thesis, Durham University, 1996. http://etheses.dur.ac.uk/5195/.

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A number of different ways of using galaxy clusters to provide information concerning fundamental cosmological parameters are considered. Using the observed local cluster X-ray temperature function in conjunction with the Press-Schechter formalism, the normalisation of a CDM power spectrum is found to be σ(_8) = (0.52 ± 0.04)Ω(_o)(^-0.46+0.10Ωo) if Ʌ(_o) = 0 or σ(_8) = (0.52 ± 0.04)Ω(_o)(^-0.52+0.13Ωo) if Ʌ(_o) = 1 — Ω(_0). This result is employed to provide detailed predictions for the abundance of clusters at high redshift, and the differences between predictions for various cosmologies are emphasised. New tests using available high-redshift cluster data are presented. For the adopted power spectrum normalisation, it is found that an Ω(_o) = 0.3, Ʌ(_o) = 0 cosmology vastly overpredicts the number of clusters that were actually found with 0.4 < z < 0.6 in the Extended Medium Sensitivity Survey. The rapid variation in the expected abundance with both σ(_8) and the assumed scatter in the L(_x) – T_x) relation limits the significance of this result, but this model is still ruled out at the ~ 95% confidence level. Order statistics are utilised to calculate the probability of finding extremely massive clusters at high redshifts. With presently available observations, no interesting upper limit can yet be placed on Ω(_o). Systematic variations in the cluster-cluster correlation length calculated using numerical simulations and resulting from the definition of clusters, the chosen σ(_8), the mean intercluster separation and whether or not redshift space distortions are included, are found to exceed the statistical errors on the measurements. Although the uncertainty in ε(_cc) derived from an ensemble of 10 Standard CDM simulations is not sufficient at large separations to remove the discrepancy between this model and results from the APM Cluster Survey, this does suggest that the level at which such a scenario has previously been rejected using ε(_cc) should be significantly reduced. Details and a few tests of a procedure for improving mass and spatial resolution in cosmological simulations are presented. After showing that a coarse-sampling technique can be used to represent the large-scale forces sufficiently accurately, the method is then used to perform ten simulations of clusters forming in an Ω(_o) = 0.3, Ʌ(_o) = 0.7 CDM cosmology. To incorporate non-radiative gas, an SPH code adapted to work on a GRAPEsupercomputer is used. The resulting clusters are found to have virial radii in good agreement with the predictions of the spherical collapse model, dark matter density profiles well described by the 'NFW formula and isothermal central gas components, with temperatures dropping by a factor of ~ 2 near the virial radius. The evolution of these properties is studied as well as that of the bulk quantities describing the clusters, with particular reference to the β parameters relating cluster gas temperatures with virial mass or velocity dispersion. Slightly greater evolution in the luminosity is seen than in previous Ω(_o) = 1 simulations, suggesting that the improved resolution is important. The β parameter relevant to the normalisation of the mass fluctuation spectrum is found to be 0.98 ± 0.07.
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Ruggiero, Rafael. "Galaxy Evolution in Clusters." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/14/14131/tde-14022019-140755/.

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In this thesis, we aim to further elucidate the phenomenon of galaxy evolution in the environment of galaxy clusters using the methodology of numerical simulations. For that, we have developed hydrodynamic models in which idealized gas-rich galaxies move within the ICM of idealized galaxy clusters, allowing us to probe in a detailed and controlled manner their evolution in this extreme environment. The main code used in our simulations is RAMSES, and our results concern the changes in gas composition, star formation rate, luminosity and color of infalling galaxies. Additionally to processes taking place inside the galaxies themselves, we have also described the dynamics of the gas that is stripped from those galaxies with unprecedented resolution for simulations of this nature (122 pc in a box including an entire 1e14 Msun cluster), finding that clumps of molecular gas are formed within the tails of ram pressure stripped galaxies, which proceed to live in isolation within the ICM of a galaxy cluster for up to 300 Myr. Those molecular clumps possibly represent a new class of objects; similar objects have been observed in both galaxy clusters and groups, but no comprehensive description of them has been given until now. We additionally create a hydrodynamic model for the A901/2 multi-cluster system, and correlate the gas conditions in this model to the locations of a sample of candidate jellyfish galaxies in the system; this has allowed us to infer a possible mechanism for the generation of jellyfish morphologies in galaxy cluster collisions in general.
Nesta tese, nós visamos a contribuir para o entendimento do fenômeno da evolução de galáxias no ambiente de aglomerados de galáxias usando a metodologia de simulações numéricas. Para isso, desenvolvemos modelos hidrodinâmicos nos quais galáxias idealizadas ricas em gás movem-se em meio ao gás difuso de aglomerados de galáxias idealizados, permitindo um estudo detalhado e controlado da evolução destas galáxias neste ambiente extremo. O principal código usado em nossas simulações é o RAMSES, e nossos resultados tratam das mudanças em composição do gás, taxa de formação estelar, luminosidade e cor de galáxias caindo em aglomerados. Adicionalmente a processos acontecendo dentro das próprias galáxias, nós também descrevemos a dinâmica do gás que é varrido dessas galáxias com resolução sem precedentes para simulações dessa natureza (122 pc em uma caixa incluindo um aglomerado de 1e14 Msun inteiro), encontrando que aglomerados de gás molecular são formados nas caudas de galáxias que passaram por varrimento de gás por pressão de arraste, aglomerados estes que procedem a viver em isolamento em meio ao gás difuso de um aglomerado de galáxias por até 300 Myr. Esses aglomerados moleculares possivelmente representam uma nova classe de objetos; objetos similares foram previamente observados tanto em aglomerados quanto em grupos de galáxias, mas um tratamento compreensivo deles não foi apresentado até agora. Nós adicionalmente criamos um modelo hidrodinâmico para o sistema multi-aglomerado A901/2, e correlacionamos as condições do gás nesse modelo com a localização de uma amostra de galáxias jellyfish nesse sistema; isso nos permitiu inferir um possível mecanismo para a geração de morfologias jellyfish em colisões de aglomerados de galáxias em geral.
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Contini, Emanuele. "Galaxy populations in clusters and proto-clusters." Doctoral thesis, Università degli studi di Trieste, 2014. http://hdl.handle.net/10077/9964.

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2012/2013
The aim of my Thesis is to explore the physical properties of the galaxy population in clusters and proto-clusters. A large number of physical processes plays an important role in the formation and evolution of galaxies: cooling, that allows the condensation of gas in the centre of dark matter haloes; star formation, that converts cold gas in stars; feedback from Active Galactic Nuclei (AGN), that prevents the gas in the central regions of haloes from "over-cooling"; feedback from Supernovae, which liberates energy in the surrounding, mixing the gas and enriching it with heavy metals. Galaxy clusters are special environments in which additional important processes take place, and play an important role in the evolution of the cluster galaxy population. Galaxy merging, harassments, tidal interactions, ram pressure stripping and strangulation are all processes acting in dense environments such as clusters of galaxies. I will take advantage of a {\it state of the art}-semi-analytic model of galaxy formation and of a set of 27 high-resolution dark matter only simulations: the semi-analytic model is based on physically motivated and observationally constrained prescriptions for the physical processes listed above and makes use of merger-trees extracted from the simulations to generate mock catalogues of galaxies. First, I make use of this set of simulations to carry out a statistical study of dark matter substructures. In the framework of modern theories of galaxy formation, dark matter substructures can be considered as the birth-sites of luminous galaxies. Therefore, the analysis of subhaloes, and in particular of their mass and spatial distributions, merger and mass accretion histories, provides important information about the expected properties of galaxies in the framework of hierarchical galaxy formation models. I have studied the amount and distribution of dark matter substructures within dark matter haloes, focusing mainly on the measured properties of subhaloes as a function of the mass and physical properties of their parent haloes, and redshift. I show that the fraction of halo mass in substructures increases with increasing mass, reaching $10 \%$ for haloes with mass of the order of $10^{15} \,M_{\odot} \hm$. The scatter in the relation is driven by halo concentration, with less concentrated haloes having larger fractions of mass in substructures. Most of this mass is locateted in the external regions of the parent haloes, in relatively few, but massive subhaloes, thus giving rise to a mass segregation which appears to be stronger at increasing redshift. Tidal stripping is found to be the process responsible for that. In fact, haloes that are more massive at the time of accretion, and that are supposed to host more luminous galaxies, are brought closer to the centre on shorter time-scales by dynamical friction, and therefore suffer of a more significant stripping. The results confirm that the main properties of galaxies, such as luminosity or stellar mass, are related to the mass of subhalos at infall, as found in previous studies.. The main results discussed in this part of the Thesis have been published in Contini et al. (2012), MNRAS.420.2978C. In a second part, I describe the implementation of physical processes responsible for the generation of the Intra-Cluster Light (ICL) in the available semi-analytic model, that, in its original form, does not account for them. The inclusion of these physical processes is, thus, an important improvement of the model. I take advantage of this upgrade of the model to investigate the origin of the ICL and to understand how the main properties of galaxies change with respect to a model that does not include these additional prescriptions. I find the fraction of ICL in groups and clusters predicted by the model to range between $10 \%$ and $40 \%$, with a large scatter and no halo mass dependence. Large part of the scatter on cluster scales is due to a range of dynamical histories, while on smaller scales it is mainly driven by individual accretion events and stripping of relatively massive satellites, with mass of the order of $10^{10.5} \, M_{\odot} \hm$, found to be the major contributors to the ICL. The ICL forms very late, below $ z \sim 1$ and a non negligible fraction (between $5 \%$ and $25 \%$) has been accreted during the hierarchical growth of haloes. Moreover, the ICL is made of stars which cover a relatively large range of metallicity, with the bulk of them being sub-solar, in agreement with recent observational data. The main results of this analysis have been submitted to MNRAS (Contini et al. 2013). In the last part of the thesis, the updated model is used to investigate the properties of the galaxy population in proto-cluster regions. The work is still in progress. I am testing the predictions of the semi-analytic model and comparing them with observations in terms of properties such as galaxy colours, star formation and stellar mass. A preliminary analysis of one very massive proto-cluster region shows that the galaxy population gets red and tend to cluster around the most massive galaxy as time goes by. There are, in literature, only a few attempts to probe such peculiar regions of the Universe from a theoretical point of view. The novelty of this work lies in the connection between massive clusters observed in the local Universe and the proto-cluster regions from which they have formed. I will try to define what a proto-cluster region is, and how it looks like, by studying the main properties of progenitors it contains. Specifically, I will investigate the spatial and velocity distributions of galaxies in simulated proto-clusters, looking at the red and blue galaxy distributions in these regions, as well as at BCG and satellite properties as a function of redshift. The main results of this work will be the subject of a paper in preparation.
XXV Ciclo
1982
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Martinet, Nicolas. "Galaxy clusters : a probe to galaxy evolution and cosmology." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066348/document.

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Cette thèse présente un certain nombre de résultats récents à propos de l'évolution des galaxies et la cosmologie, à partir de l'observation d'amas de galaxies en lumière visible. Nous introduisons d'abord les principales propriétés des amas de galaxies (Chapitre 1.1) et la façon dont ces objets permettent de contraindre le modèle cosmologique standard (Chapitre 1.2). Une grande partie des résultats présentés ici ont été obtenus à partir de l'étude du relevé d'amas DAFT/FADA, qui regroupe des amas dans la gamme de décalages spectraux 0.4
This thesis presents some recent results concerning galaxy evolution and cosmology,based on the observation of galaxy clusters at optical wavelengths. We first introduce the main properties of galaxy clusters (Sect. 1.1) and how they can be used for cosmology within the standard cosmological model (Sect. 1.2). A large fraction of the presented results comes from the study of the DAFT/FADA galaxy cluster survey at redshifts 0.4 < z < 0.9 (Sect. 1.3). We divide our study in two parts according to the observable that is considered: galaxy luminosity or galaxy shape. The distribution of galaxy luminosities is called the galaxy luminosity function (GLF), which can be used to probe the evolution of cluster galaxies (Sect. 2.1). Computing the GLFs for a sub sample of 25 DAFT/FADA clusters, we find that faint blue star forming galaxies are quenched into red quiescent galaxies from high redshift until today. Comparing to the field shows that this transformation is more efficient in high density environments.We also study the fraction of baryons in galaxy groups and clusters (Sect. 2.2). Wefind that in groups, the stars contained in galaxies can reach masses of the same order as those of the intra-cluster gas, while in clusters they are usually negligible relatively to the gas. Taking both stars and gas into account we constrain the matter density parameter Galaxy shapes are distorted by foreground objects that bend light in their vicinity. This lensing signal can be exploited to measure the mass distribution of a foreground cluster. We review the basic theory of weak lensing and shear measurement (Sect. 3.1), and then apply it to a subsample of 16 DAFT/FADA clusters, with Subaru/SuprimeCam or CFHT/MegaCam imaging (Sect. 3.2). We estimate the masses of these clusters, and take advantage of the large fields of view of our images to detect filaments and structures in the cluster vicinity, observationally supporting the hierarchical scenario of cluster growth. Finally, we detect shear peaks in Euclid-like simulations, and use their statistics as a cosmological probe, similarly to cluster counts (Sect. 3.3). We forecast the cosmological constraints that this technique will achieve when applied to the Euclid space mission, and develop a tomographic analysis that adds information from redshifts. We conclude with a discussion of our perspectives on future studies in all the fieldsinvestigated in the present thesis
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Kim, Jae Woo. "Galaxy clustering and galaxy clusters from the UKIDSS DXS." Thesis, Durham University, 2011. http://etheses.dur.ac.uk/3270/.

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Recent wide and deep surveys allow us to investigate the large scale structure of the Universe at high redshift. We present studies of the clustering of high redshift galaxies and galaxy clusters, using reprocessed UKIDSS DXS catalogues. The UKIDSS DXS is one of the deepest near-IR surveys to date and provides sufficient samples of the distant Universe. Firstly we measure the angular correlation function of high redshift red galaxies which are Extremely Red Objects (EROs) and Distant Red Galaxies (DRGs) in Chapters 3 and 4 from DXS SA22 and Elais-N1 fields. We found that their angular correlation functions can be described by a broken power-law. Thus we estimated clustering properties on small and large scales separately. Then we found that red or bright samples are more strongly clustered than those having the opposite characteristics. In addition old, passive EROs are found to be more clustered than dusty, star-forming EROs. The effect of cosmic variance on angular clustering was also investigated. Chapter 5 describes the halo modelling for the angular clustering of EROs. EROs reside in in dark matter haloes having > 1012.9h−1M, and have a bias of 1.93 at z = 1.12 and 3.17 at z = 1.55. From a direct comparison between the observed clustering and the cosmological model, they show good agreement. However the cosmological simulation may predict too many red satellites, especially at high redshfit. In Chapter 6, we present the details of our cluster detection algorithm based on the red sequence technique. This algorithm successfully found published galaxy clusters in the DXS Elais-N1 field. We also found many overdensities in the DXS SA22 field. Two prominent galaxy clusters were confirmed by spectroscopic observations, and we identified a supercluster candidate. Finally the clustering strength of candidate galaxy clusters showed good agreement with previous results and was consistent with the ΛCDM prediction. In the near future the full DXS catalogue will provide an opportunity to detect various high redshift populations. With other advanced surveys, it will be possible to investigate more details of the large scale structure of the Universe.
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Harrison, Ian. "Cosmology with extreme galaxy clusters." Thesis, Cardiff University, 2013. http://orca.cf.ac.uk/56777/.

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This thesis describes the use of the rarest high-mass and high-redshift galaxy clusters to constrain cosmology, with a particular focus on the methodology of Extreme Value Statistics (EVS). Motivated by the prospect that even a single sufficiently high mass and high redshift cluster can provide strong evidence against a given cosmology, we first use exact EVS to construct the probability density function (PDF) for the mass of the most-massive cold dark matter (CDM) halo within a fixed redshift volume. We find that the approximation of uncorrelated haloes is valid for high mass haloes 10¹⁵ and large volumes 100⁻¹Mpc, which are also required before the shape of the PDF converges to an asymptotic Generalised Extreme Value (GEV) form. Furthermore, we show the GEV shape parameter γ to be a weak discriminant of primordial non-Gaussianity on galaxy cluster scales. We then extend this analysis to real observations, predicting the PDF for the most-massive galaxy cluster within an observational survey, showing no cluster so far observed is significantly larger than the most-massive expected at its redshift in a concordance cosmology. We also show how the predictions for most-massive cluster with redshift are changed in cosmologies with primordial non-Gaussianity or coupled scalar field dark energy. Finally, we consider why this result appears at odds with some previous analyses, reaffirming that they make use of a biased statistic and showing how an equivalent unbiased one may be constructed. This is then used to rank a comprehensive sample of galaxy clusters according to their rareness, with the cluster ACT-CLJ0102-4915 found to be the most extreme object so far observed. However, the observation of this (and all other clusters so far seen) is shown to be a not unusual event in a concordance universe.
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Gruen, Daniel. "Weak lensing by galaxy clusters." Diss., Ludwig-Maximilians-Universität München, 2015. http://nbn-resolving.de/urn:nbn:de:bvb:19-183024.

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Der Ursprung und die Entwicklung unseres Universums zeigt sich gleichermaßen in der Raumzeit selbst wie in den Strukturen, die in ihr entstehen. Galaxienhaufen sind das Ergebnis hierarchischer Strukturbildung. Sie sind die massivsten Objekte, die sich im heutigen Universum bilden konnten. Aufgrund dieser Eigenschaft ist ihre Anzahl und Struktur hochgradig abhängig von der Zusammensetzung und Evolution des Universums. Die Messung der Anzahldichte von Galaxienhaufen beruht auf Katalogen, die nach einer beobachtbaren Größe ausgewählt werden. Die Anwendung einer Massen-Observablen-Relation (MOR) erlaubt es, die beobachtete Anzahl als Funktion der Observablen und der Rotverschiebung mit Vorhersagen zu vergleichen und so kosmologische Parameter zu bestimmen. Man kann jedoch zu Recht behaupten, dass diese Messungen noch nicht präzise im Prozentbereich sind. Hauptgrund hierfür ist das unvollständige Verständnis der MOR. Ihre Normalisierung, die Skalierung der Observablen mit Masse und Rotverschiebung und die Größe und Korrelation von intrinsischen Streuungen muss bekannt sein, um Anzahldichten korrekt interpretieren zu können. Die Massenbestimmung von Galaxienhaufen durch die differenzielle Lichtablenkung in ihrem Gravitationsfeld, i.e. durch den so genannten schwachen Gravitationslinseneffekt (weak lensing), kann erheblich hierzu beitragen. In dieser Arbeit werden neue Methoden und Ergebnisse solcher Untersuchungen vorgestellt. Zu ersteren gehören, als Teil der Datenaufbereitung, (i) die Korrektur von CCD-Bildern für nichtlineare Effekte durch die elektrischen Felder der angesammelten Ladungen (Kapitel 2) und (ii) eine Methode zur Maskierung von Artefakten in überlappenden Aufnahmen eines Himmelsbereichs durch Vergleich mit dem Median-Bild (Kapitel 3). Schließlich ist (iii) eine Methode zur Selektion von Hintergrundgalaxien, basierend auf deren Farbe und scheinbarer Magnitude, die eine neue Korrektur für die Kontamination durch Mitglieder des Galaxienhaufens einschließt, im Abschnitt 5.3.1 beschrieben. Die wissenschaftlichen Hauptergebnisse sind die folgenden. (i) Für den Hubble Frontier Field-Haufen RXC J2248.7-4431 bestimmen wir Masse und Konzentration mittels weak lensing und bestätigen die durch Röntgen- und Sunyaev-Zel'dovich-Beobachtungen (SZ) vorhergesagte große Masse. Die Untersuchung von Haufengalaxien zeigt die Abhängigkeit von Morphologie und Leuchtkraft sowie Umgebung (Kapitel 4). (ii) Unsere Massenbestimmung für 12 Galaxienhaufen ist konsistent mit Röntgenmassen, die unter Annahme hydrostatischen Gleichgewichts des heißen Gases gemacht wurden. Wir bestätigen die MOR, die für die Signifikanz der Detektion mit dem South Pole Telescope bestimmt wurde. Wir finden jedoch Diskrepanzen zur Planck-SZ MOR. Unsere Vermutung ist, dass diese mit einer flacheren Steigung der MOR oder einem größen-, rotverschiebungs- oder rauschabhängigen Problem in der Signalextraktion zusammenhängt (Kapitel 5). (iii) Schließlich zeigen wir, durch die Verbindung von Simulationen und theoretischer Modellierung, dass die Variation von Dichteprofilen bei fester Masse signifikant zur Ungenauigkeit von Massenbestimmungen von Galaxienhaufen mittels weak lensing beiträgt. Ein Modell für diese Variationen, wie das hier entwickelte, ist daher wichtig für die genaue Bestimmung der MOR, wie sie für kommende Untersuchungen nötig sein wird (Kapitel 6).
The story of the origin and evolution of our Universe is told, equivalently, by space-time itself and by the structures that grow inside of it. Clusters of galaxies are the frontier of bottom-up structure formation. They are the most massive objects to have collapsed at the present epoch. By that virtue, their abundance and structural parameters are highly sensitive to the composition and evolution of the Universe. The most common probe of cluster cosmology, abundance, uses samples of clusters selected by some observable. Applying a mass-observable relation (MOR), cosmological parameters can be constrained by comparing the sample to predicted cluster abundances as a function of observable and redshift. Arguably, however, cluster probes have not yet entered the era of per cent level precision cosmology. The primary reason for this is our imperfect understanding of the MORs. The overall normalization, the slope of mass vs. observable, the redshift evolution, and the degree and correlation of intrinsic scatters of observables at fixed mass have to be constrained for interpreting abundances correctly. Mass measurement of clusters by means of the differential deflection of light from background sources in their gravitational field, i.e. weak lensing, is a powerful approach for achieving this. This thesis presents new methods for and scientific results of weak lensing measurements of clusters of galaxies. The former include, on the data reduction side, (i) the correction of CCD images for non-linear effects due to the electric fields of accumulated charges (Chapter 2) and (ii) a method for masking artifact features in sets of overlapping images of the sky by comparison to the median image (Chapter 3). Also, (iii) I develop a method for the selection of background galaxy samples based on their color and apparent magnitude that includes a new correction for contamination with cluster member galaxies (Section 5.3.1). The main scientific results are the following. (i) For the Hubble Frontier Field cluster RXC J2248.7--4431 our lensing analysis constrains mass and concentration of the cluster halo and we confirm the large mass predicted by X-ray and Sunyaev-Zel'dovich (SZ) observations. The study of cluster members shows the relation of galaxy morphology to luminosity and environment (Chapter 4). (ii) Our lensing mass measurements for 12 clusters are consistent with X-ray masses derived under the assumption of hydrostatic equilibrium of the intra-cluster gas. We confirm the MORs derived by the South Pole Telescope collaboration for the detection significance of the cluster SZ signal in their survey. We find discrepancies, however, with the Planck SZ MOR. We hypothesize that these are related either to a shallower slope of the MOR or a size, redshift or noise dependent bias in SZ signal extraction (Chapter 5). (iii) Finally, using a combination of simulations and theoretical models for the variation of cluster profiles at fixed mass, we find that the latter is a significant contribution to the uncertainty of cluster lensing mass measurements. A cosmic variance model, such as the one we develop, is necessary for MOR constraints to be accurate at the level required for future surveys (Chapter 6).
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Wilson, Gillian. "Gravitational lensing and galaxy clusters." Thesis, Durham University, 1995. http://etheses.dur.ac.uk/5310/.

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Kaiser & Squires have proposed a technique for mapping the dark matter in galaxy clusters using the coherent weak distortion of background galaxy images caused by gravitational lensing. We investigate the effectiveness of this technique under controlled conditions by creating simulated CCD frames containing galaxies lensed by a model cluster, measuring the resulting galaxy shapes, and comparing the reconstructed mass distribution with the original. Typically, the reconstructed surface density is diminished in magnitude when compared to the original. The main cause of this reduced signal is the blurring of galaxy images by atmospheric seeing, but the overall factor by which the reconstructed surface density is reduced depends also on the signal-to-noise ratio in the CCD frame and on both the sizes of galaxy images and the magnitude limit of the sample that is analysed. We propose a method for estimating a multiplicative compensation factor, f, directly from a CCD frame which can then be used to correct the surface density estimates given by the Kaiser & Squires formalism. We test our technique using a lensing cluster drawn from a cosmological N-body simulation with a variety of realistic background galaxy populations and observing conditions. We conclude that weak lensing observations when calibrated using this method yield not only accurate maps of the cluster morphology but also quantitative estimates of the cluster mass distribution. We then show that weak lensing simulations by rich clusters can be used to constrain the likely range of values of the cosmological constant Ω(_0). Again employing the Kaiser & Squires mass density estimator, we model the lensing induced by a number of simulated clusters from three different cosmologies. We introduce new statistics which are independent of any uncertainties in the surface density mentioned above. We conclude that lensing observations of a small number of clusters should be sufficient to place broad constraints on Ω(_0) and certainly distinguish between the extreme values of 0.2 and 1.We also present deep two-colour photometry of two rich clusters at z = 0.18; A1689 and A665. We use the data to construct number counts as a function of magnitude. To the magnitude depth we were able to probe, we conclude that there is no strong evidence for a steep faint end slope to the galaxy luminosity functioning moderate-redshift clusters.
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Henson, Monique. "Cosmological simulations of galaxy clusters." Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/cosmological-simulations-of-galaxy-clusters(c726f7ad-2c0b-4134-9d89-e0b364b07741).html.

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Galaxy clusters are the most massive collapsed structures in the Universe and their properties offer a crucial insight into the formation of structure. High quality observational data is forthcoming with ongoing and upcoming surveys, but simulations are needed to provide robust theoretical predictions for comparison, as well mock data for testing observational techniques. Numerical simulations are now able to accurately model a range of astrophysical processes. This is highlighted in the BAHAMAS and MACSIS simulations, which have successfully reproduced the observed scaling relations of galaxy clusters. We use these simulations to quantify the impact baryons have on the mass distribution within galaxy clusters, as well as the bias in X-ray and weak lensing mass estimates. It is shown that baryons have only a minor affect on the spins, shape and density profiles of galaxy clusters and they have no significant impact on the bias in weak lensing mass estimates. When using spectroscopic temperatures and densities, the X-ray hydrostatic mass bias decreases as a function of mass, leading to a bias of ~40% for clusters with M_500 > 10^15 solar masses. In the penultimate chapter, we use the EAGLE and C-EAGLE simulations to construct more realistic mock cluster observations. The EAGLE simulations have been shown to successfully reproduce the properties of field galaxies and they are complemented by the C-EAGLE project, which extends this work to the cluster scale. We use these simulations to construct a cluster lightcone that accounts for the impact of uncorrelated large scale structure on cluster observables, including weak lensing mass estimates, the Sunyaev-Zel'dovich parameter and X-ray luminosity.
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Books on the topic "Galaxy clusters"

1

Feretti, L., I. M. Gioia, and G. Giovannini. Merging processes in galaxy clusters. Dordrecht: Springer, 2011.

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Space Telescope Science Institute (U. Superclustering of Galaxy Clusters. S.l: s.n, 1985.

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Feretti, L., I. M. Gioia, and G. Giovannini, eds. Merging Processes in Galaxy Clusters. Dordrecht: Springer Netherlands, 2002. http://dx.doi.org/10.1007/0-306-48096-4.

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L, Feretti, Gioia I. M, and Giovannini G, eds. Merging processes in galaxy clusters. Dordrecht: Kluwer Academic Publishers, 2002.

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L, Feretti, Gioia I. M, and Giovannini G, eds. Merging processes in galaxy clusters. Dordrecht: Kluwer Academic Publishers, 2002.

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Adrian, Melott, and United States. National Aeronautics and Space Administration., eds. Decaying neutrinos in galaxy clusters. [Washington, D.C: National Aeronautics and Space Administration, 1993.

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Lobo, Catarina, Margarida Serote Roos, and Andrea Biviano, eds. Galaxy Evolution in Groups and Clusters. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-010-0107-6.

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Hartog, Roland Henrik den. The dynamics of rich galaxy clusters: Proefschrift. Leiden: Sterrewacht, 1995.

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Fisher, Karl. Galaxy clustering around nearby luminous quasars. [Washington, D.C.]: NASA, 1997.

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David, Merritt. Galaxy Dynamics: A Rutgers Symposium. San Francisco, Calif: Astronomical Society of the Pacific, 1999.

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Book chapters on the topic "Galaxy clusters"

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Hodge, Paul. "Open Clusters." In The Andromeda Galaxy, 163–82. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-015-8056-4_11.

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Hodge, Paul. "Globular Clusters." In The Andromeda Galaxy, 124–44. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-015-8056-4_9.

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Hodge, Paul. "Clusters and Associations." In The Spiral Galaxy M33, 57–71. Dordrecht: Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-94-007-2025-1_6.

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Yee, H. K. C. "Galaxy Clusters Around Quasars." In Clusters and Superclusters of Galaxies, 293–309. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2482-9_17.

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Ellingson, E. "Galaxy Evolution in Clusters." In Galaxy Evolution in Groups and Clusters, 9–18. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-010-0107-6_1.

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Birdi, K. S. "Galaxy Clusters and Fractals." In Fractals in Chemistry, Geochemistry, and Biophysics, 165–72. Boston, MA: Springer US, 1993. http://dx.doi.org/10.1007/978-1-4899-1124-7_7.

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Silk, Joseph. "Galaxy Formation in Galaxy Clusters: A Phenomenological Approach." In Cosmological Aspects of X-Ray Clusters of Galaxies, 293–98. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-1022-8_31.

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Sanders, D. B., D. P. Clemens, N. Z. Scoville, and P. M. Solomon. "Molecular-Cloud Clusters and Chains." In The Milky Way Galaxy, 329–30. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-5291-1_67.

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Frenk, Carlos S. "Galaxy Clusters and the Epoch of Galaxy Formation." In The Epoch of Galaxy Formation, 257–64. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-009-0919-9_28.

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White, Simon D. M. "The Structure of Galaxy Clusters." In Clusters and Superclusters of Galaxies, 17–28. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2482-9_2.

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Conference papers on the topic "Galaxy clusters"

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Manchester, R. N. "Globular clusters and pulsars." In Back to the Galaxy. AIP, 1992. http://dx.doi.org/10.1063/1.43928.

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Romeo, Alessio D., Jesper Sommer-Larsen, and Laura Portinari. "Simulating galaxy clusters : the ICM and the galaxy populations." In Baryons in Dark Matter Halos. Trieste, Italy: Sissa Medialab, 2004. http://dx.doi.org/10.22323/1.014.0075.

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Brunetti, Gianfranco. "Gamma rays from galaxy clusters." In HIGH ENERGY GAMMA-RAY ASTRONOMY: 6th International Meeting on High Energy Gamma-Ray Astronomy. Author(s), 2017. http://dx.doi.org/10.1063/1.4968894.

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Fusco-Femiano, Roberto, Alfonso Cavaliere, Andrea Lapi, A. Comastri, L. Angelini, and M. Cappi. "Supermodel Analysis of Galaxy Clusters." In X-RAY ASTRONOMY 2009; PRESENT STATUS, MULTI-WAVELENGTH APPROACH AND FUTURE PERSPECTIVES: Proceedings of the International Conference. AIP, 2010. http://dx.doi.org/10.1063/1.3475237.

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Parrish, I. J., E. Quataert, P. Sharma, Sebastian Heinz, and Eric Wilcots. "Beyond MHD in Galaxy Clusters." In THE MONSTER’S FIERY BREATH: FEEDBACK IN GALAXIES, GROUPS, AND CLUSTERS. AIP, 2009. http://dx.doi.org/10.1063/1.3293076.

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Kopylova, F., and A. Kopylov. "Study of groups/clusters of galaxies with the SDSS." In ASTRONOMY AT THE EPOCH OF MULTIMESSENGER STUDIES. Proceedings of the VAK-2021 conference, Aug 23–28, 2021. Crossref, 2022. http://dx.doi.org/10.51194/vak2021.2022.1.1.148.

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For a large sample of groups/clusters of galaxies (N =185), we obtained the scaling relations among of their photometricaland dynamical parameters. We find:0.77±0.011. that in the virialized regions of the galaxy systems the total luminosity increase with mass L K ∝ M 200(M K <−21. m 0);2. that the new halo boundary of the galaxy systems corresponds to the splashback radius R sp . These radius is definedby the observed intergrated distribution of the number of galaxies as a function of the angular distance from thegroup/cluster center squared;3. that the fraction of galaxies with quenched star formation is maximal in the central regions of the galaxy systems,and it decreases to the radius R sp , but remains higher than in the field on ∼ 27%.
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Victor Ribeiro de Jesus, João, and Rodrigo Lyra. "Um Estudo Sobre Identificação de Aglomerados de Galáxias." In Computer on the Beach. Itajaí: Universidade do Vale do Itajaí, 2020. http://dx.doi.org/10.14210/cotb.v11n1.p048-049.

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Galaxy clusters are fundamental blocks of our universe, like stars and galaxies. The study of galaxy clusters has shown complexity due to a large number of stars superimposed on these clusters, which emit light and block the clear optical band visualization of the phenomenon. In this paper, we present the implementation of an algorithm capable of classifying and remove the stars of spatial images. The purpose is to improve not only the existing studies around galaxy clusters but also to assist the developing in astronomic researches with available treated spatial images.
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Bernardi, Gianni, Tiziana Venturi, Rossella Cassano, Gianfranco Brunetti, Daniele Dallacasa, Bernard Fanaroff, Benjamin Hugo, et al. "A MeerKAT View on Galaxy Clusters." In MeerKAT Science: On the Pathway to the SKA. Trieste, Italy: Sissa Medialab, 2018. http://dx.doi.org/10.22323/1.277.0031.

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FERETTI, LUIGINA. "NON-THERMAL PHENOMENA IN GALAXY CLUSTERS." In Proceedings of the XXI Symposium on Relativistic Astrophysics. WORLD SCIENTIFIC, 2003. http://dx.doi.org/10.1142/9789812704009_0019.

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Zhang, Yu-Ying, A. Comastri, L. Angelini, and M. Cappi. "Galaxy Clusters: Substructure and Mass Systematics." In X-RAY ASTRONOMY 2009; PRESENT STATUS, MULTI-WAVELENGTH APPROACH AND FUTURE PERSPECTIVES: Proceedings of the International Conference. AIP, 2010. http://dx.doi.org/10.1063/1.3475244.

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Reports on the topic "Galaxy clusters"

1

Wiesner, Matthew P. Investigations of Galaxy Clusters Using Gravitational Lensing. Office of Scientific and Technical Information (OSTI), August 2014. http://dx.doi.org/10.2172/1155188.

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Miller, Christopher J. Complementary Probes of Dark Energy using Galaxy Clusters. Office of Scientific and Technical Information (OSTI), July 2018. http://dx.doi.org/10.2172/1461837.

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Frye, Brenda Louise. A faint galaxy redshift survey behind massive clusters. Office of Scientific and Technical Information (OSTI), May 1999. http://dx.doi.org/10.2172/764393.

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Gruen, Daniel. Weak Lensing by Galaxy Clusters: from Pixels to Cosmology. Office of Scientific and Technical Information (OSTI), March 2015. http://dx.doi.org/10.2172/1221338.

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George, Matt. An Automated Method for Characterizing the Relaxedness of Galaxy Clusters. Office of Scientific and Technical Information (OSTI), December 2005. http://dx.doi.org/10.2172/877476.

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Sheldon, Erin S., David E. Johnston, Ryan Scranton, Ben P. Koester, Timothy A. McKay, Hiroaki Oyaizu, Carlos Cunha, et al. Cross-correlation Weak Lensing of SDSS Galaxy Clusters I: Measurements. Office of Scientific and Technical Information (OSTI), September 2007. http://dx.doi.org/10.2172/917269.

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Zhang, Yuanyuan. Looking Wider and Further: The Evolution of Galaxies Inside Galaxy Clusters. Office of Scientific and Technical Information (OSTI), January 2016. http://dx.doi.org/10.2172/1248222.

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Baxter, Eric Jones. Detecting Gravitational Lensing of the Cosmic Microwave Background by Galaxy Clusters. Office of Scientific and Technical Information (OSTI), August 2014. http://dx.doi.org/10.2172/1182549.

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Johnston, David E., Erin S. Sheldon, Risa H. Wechsler, Eduardo Rozo, Benjamin P. Koester, Joshua A. Frieman, Timothy A. McKay, August E. Evrard, Matthew R Becker, and James Annis. Cross-correlation Weak Lensing of SDSS galaxy Clusters II: Cluster Density Profiles and the Mass--Richness Relation. Office of Scientific and Technical Information (OSTI), September 2007. http://dx.doi.org/10.2172/917267.

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Piacentine, J. Detection of Galaxy Clusters with the XMM-Newton Large Scale Structure Survey. Office of Scientific and Technical Information (OSTI), September 2004. http://dx.doi.org/10.2172/833122.

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