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In a previous paper we investigated means for constraining the mass distribution of cluster galaxies by weak lensing. We concluded that a comprehensive method should treat the lensing effects of individual cluster galaxies and those…

Astrophysics · Physics 2009-10-30 Bernhard Geiger , Peter Schneider

We report weak-lensing masses for 51 of the most X-ray luminous galaxy clusters known. This cluster sample, introduced earlier in this series of papers, spans redshifts 0.15 < z_cl < 0.7, and is well suited to calibrate mass proxies for…

Using photometric data from the Dark Energy Survey and the Wide-field Infrared Survey Explorer, we estimate photometric redshifts for 105 million galaxies using the nearest-neighbour algorithm. From such a large data base, 151,244 clusters…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-07 Z. L. Wen , J. L. Han

Based on the photometric redshift catalog of Zou H. et al. (2019), we apply a fast clustering algorithm to identify 540,432 galaxy clusters at $z\lesssim1$ in the DESI legacy imaging surveys, which cover a sky area of about 20,000 deg$^2$.…

Astrophysics of Galaxies · Physics 2021-04-21 Hu Zou , Jinghua Gao , Xin Xu , Xu Zhou , Jun Ma , Zhimin Zhou , Tianmeng Zhang , Jundan Nie , Jiali Wang , Suijian Xue

We present a new two-color algorithm, the "Stellar Bump Sequence" (SBS), that is optimized for robustly identifying candidate high-redshift galaxy clusters in combined wide-field optical and mid-infrared (MIR) data. The SBS algorithm is a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Adam Muzzin , Gillian Wilson , Ricardo Demarco , Chris Lidman , Julie Nantais , Henk Hoekstra , H. K. C. Yee , Alessandro Rettura

According to the current cosmological paradigm, large scale structures form hierarchically in the Universe. Clusters of galaxies grow through a continuous accretion of mass. Nevertheless, the rate and manner of mass accretion events are…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 J. Alfonso L. Aguerri , Ruben Sanchez-Janssen

We predict the amplitude of the gravitational redshift of galaxies in galaxy clusters using an N-body simulation of a Lambda CDM universe. We examine if it might be possible to detect the gravitational effect on the total redshift observed…

Astrophysics · Physics 2009-11-10 Young-Rae Kim , Rupert Croft

We propose a new technique, which we call the lens parallax method, to determine simultaneously the redshift distribution of the faint blue galaxies and the mass distributions of foreground clusters of galaxies. The method is based on…

Astrophysics · Physics 2009-10-28 Matthias Bartelmann , Ramesh Narayan

We explore the accuracy of the clustering-based redshift inference within the MICE2 simulation. This method uses the spatial clustering of galaxies between a spectroscopic reference sample and an unknown sample. The goal of this study is to…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-27 V. Scottez , A. Benoit-Lévy , J. Coupon , O. Ilbert , Y. Mellier

Context. An automatic tool to derive structural parameters of semi-resolved star clusters located in crowded stellar fields in nearby galaxies is needed for homogeneous processing of archival frames. Aims. We have developed a program that…

Astrophysics of Galaxies · Physics 2015-12-31 D. Narbutis , D. Semionov , R. Stonkutė , P. de Meulenaer , T. Mineikis , A. Bridžius , V. Vansevičius

The structure of defect clusters formed in a displacement cascade plays a significant role in the micro-structural evolution during irradiation. Molecular dynamics simulations have been widely used to study collision cascades and subsequent…

Computational Physics · Physics 2024-02-02 Utkarsh Bhardwaj , Andrea E. Sand , Manoj Warrier

This is the third paper in a series which combines N-body simulations and semi-analytic modelling to provide a fully spatially resolved simulation of the galaxy formation and clustering processes. Here we extract mock redshift surveys from…

The goal of this paper is to provide a method, which is able to find categories of traffic scenarios automatically. The architecture consists of three main components: A microscopic traffic simulation, a clustering technique and a…

Signal Processing · Electrical Eng. & Systems 2020-04-08 Friedrich Kruber , Jonas Wurst , Eduardo Sánchez Morales , Samarjit Chakraborty , Michael Botsch

We develop a method to identify proto-clusters based on dark matter halos represented by galaxy groups selected from surveys of galaxies at high redshift. We test the performance of this method on halos in N-body simulations, and find it…

Astrophysics of Galaxies · Physics 2021-06-30 Kai Wang , H. J. Mo , Cheng Li , Yangyao Chen

We compare the existent methods including the minimum spanning tree based method and the local stellar density based method, in measuring mass segregation of star clusters. We find that the minimum spanning tree method reflects more the…

Astrophysics of Galaxies · Physics 2017-06-14 Jincheng Yu , Thomas H. Puzia , Congping Lin , Yiwei Zhang

Galaxy-scale strong lenses in galaxy clusters provide a unique tool to investigate their inner mass distribution and the sub-halo density profiles in the low-mass regime, which can be compared with the predictions from cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-09 G. Angora , P. Rosati , M. Meneghetti , M. Brescia , A. Mercurio , C. Grillo , P. Bergamini , A. Acebron , G. Caminha , M. Nonino , L. Tortorelli , L. Bazzanini , E. Vanzella

Two fundamental algorithm-design paradigms are Tree Search and Dynamic Programming. The techniques used therein have been shown to complement one another when solving the complete set partitioning problem, also known as the coalition…

Multiagent Systems · Computer Science 2018-08-24 Talal Rahwan , Tomasz P. Michalak

We identify galaxy groups and clusters in volume-limited samples of the SDSS redshift survey, using a redshift-space friends-of-friends algorithm. We optimize the friends-of-friends linking lengths to recover galaxy systems that occupy the…

Despite compelling theoretical arguments, the use of clusters as cosmological probes is, in practice, frequently questioned because of the many uncertainties impinging on cluster mass estimates. Our aim is to develop a fully self-consistent…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-29 M. Pierre , A. Valotti , L. Faccioli , N. Clerc , R. Gastaud , E. Koulouridis , F. Pacaud

We present a galaxy catalog simulator which turns N-body simulations with subhalos into multiband photometric mocks. The simulator assigns galaxy properties to each subhalo to reproduce the observed cluster galaxy halo occupation…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Jeeseon Song , Joseph J. Mohr , Wayne A. Barkhouse , Michael S. Warren , Cody Rude
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