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Related papers: Mass modelling of Abell 2634: avoiding the interlo…

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We examine the inner mass distribution of the relaxed galaxy cluster Abell 383 in deep 16-band HST/ACS+WFC3 imaging taken as part of the CLASH multi-cycle treasury program. Our program is designed to study the dark matter distribution in 25…

Context. Galaxy clusters are continuously growing through the accretion of matter in their outskirts. This process induces inhomogeneities in the gas density distribution (clumping) which need to be taken into account to recover the…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-26 C. Tchernin , D. Eckert , S. Ettori , E. Pointecouteau , S. Paltani , S. Molendi , G. Hurier , F. Gastaldello , E. T. Lau , D. Nagai , M. Roncarelli , M. Rossetti

We quantify the performance of mass mapping techniques on mock imaging and gravitational lensing data of galaxy clusters. The optimum method depends upon the scientific goal. We assess measurements of clusters' radial density profiles,…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-29 Sut-Ieng Tam , Richard Massey , Mathilde Jauzac , Andrew Robertson

I compare the mass values obtained with data taken from the Arcminute Microkelvin Imager (AMI) radio interferometer system and from the Planck satellite. The former of these uses a Bayesian analysis pipeline that parameterises a cluster in…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-13 Kamran Javid

Strong gravitational lensing is a unique tool to model with great accuracy the inner mass distribution of massive galaxy clusters. In particular, clusters with large Einstein radii provide a wealth of multiply imaged systems in the cluster…

Astrophysics of Galaxies · Physics 2009-11-13 Johan Richard , Liuyi Pei , Marceau Limousin , Eric Jullo , Jean-Paul Kneib

We present a gravitational lensing study of the massive galaxy cluster A2219 (redshift 0.22). This investigation is based on multicolour images from U through H, which allows photometric redshifts to be estimated for the background sources.…

Astrophysics · Physics 2007-05-23 J. Bezecourt , H. Hoekstra , M. E. Gray , H. M. AbdelSalam , K. Kuijken , R. S. Ellis

Feature selection methods have an important role on the readability of data and the reduction of complexity of learning algorithms. In recent years, a variety of efforts are investigated on feature selection problems based on unsupervised…

Machine Learning · Computer Science 2019-12-12 Mohsen Ghassemi Parsa , Hadi Zare , Mehdi Ghatee

Abell 2744, also known as Pandora's Cluster, is a complex merging galaxy cluster. While a major merger is clear along the north-south axis, the dynamical state of the northwest subcluster has been highly uncertain. We present ultra-deep…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-04 Urmila Chadayammuri , Ákos Bogdán , Gerrit Schellenberger , John ZuHone

An unsupervised classification method for point events occurring on a network of lines is proposed. The idea relies on the distributional flexibility and practicality of random partition models to discover the clustering structure featuring…

We present direct evidence of a collision of subclusters in the galaxy cluster Abell 754. Our comparison of new optical data and archival ROSAT PSPC X-ray data reveal three collision signatures predicted by n-body/hydrodynamical simulations…

Astrophysics · Physics 2009-10-28 Ann I. Zabludoff , Dennis Zaritsky

Interleaving is a mechanism universally used in wireless access technologies to alleviate the effect of channel correlation. In spite of its wide adoption, to the best of our knowledge, there are no analytical models proposed so far. In…

Information Theory · Computer Science 2018-01-31 Dmitri Moltchanov , Pavel Kustarev , Yevgeni Kucharyavy

Recent advances in engineering technologies have enabled the collection of a large number of longitudinal features. This wealth of information presents unique opportunities for researchers to investigate the complex nature of diseases and…

Methodology · Statistics 2023-11-27 Zihang Lu , Noirrit Kiran Chandra

We present a detailed study of the morphological features of 22 rich galaxy clusters. Our sample is constructed from a cross-correlation of optical (Abell+APM) data with X-ray (0.1 - 2.4) keV ROSAT pointed observations. We systematically…

I review our current knowledge of the mass distribution in clusters, as obtained from the analysis of the projected phase-space distribution of cluster galaxies. I discuss the methods of analysis, their relative advantages and…

Astrophysics · Physics 2007-05-23 Andrea Biviano

In the framework of the hierarchical model the intra-cluster medium properties of galaxy clusters are tightly linked to structure formation, which makes X-ray surveys well suited for cosmological studies. To constrain cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-07 Florian Käfer , Alexis Finoguenov , Dominique Eckert , Jeremy S. Sanders , Thomas H. Reiprich , Kirpal Nandra

We report on the detection of dark matter in the cluster of galaxies Abell~2163 using the weak gravitational distortion of background galaxies, and an analysis of the cluster X-ray emission. We find that while the qualitative distributions…

Astrophysics · Physics 2009-10-28 G. Squires , D. M. Neumann , N. Kaiser , M. Arnaud , A. Babul , H. Böhringer , G. Fahlman , D. Woods

This paper presents a sample of "cold front" clusters selected from the Chandra archive. The clusters are selected based purely on the existence of surface brightness edges in their Chandra images which are modeled as density jumps. A…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Matt S. Owers , Paul E. J. Nulsen , Warrick J. Couch , Maxim Markevitch

Upcoming emission-line spectroscopic surveys, such as Euclid and the Roman Space Telescope, will be affected by systematic effects due to the presence of interlopers: galaxies whose redshift and distance from us are miscalculated due to…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-13 Elena Massara , Francisco Villaescusa-Navarro , Will J. Percival

This article is the second in a series in which we perform an extensive comparison of various galaxy-based cluster mass estimation techniques that utilise the positions, velocities and colours of galaxies. Our aim is to quantify the…

In the realm of big data, discerning patterns in nonlinear systems affected by external control inputs is increasingly challenging. Our approach blends the coarse-graining strengths of centroid-based unsupervised clustering with the clarity…

Fluid Dynamics · Physics 2023-12-25 Nitish Arya , Aditya G. Nair