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Related papers: Uncovering substructure with wavelets: proof of co…

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We present a study of the substructure finder dependence of subhalo clustering in the Aquarius Simulation. We run 11 different subhalo finders on the haloes of the Aquarius Simulation and we study their differences in the density profile,…

Abell 1689 is a galaxy cluster at $z=0.183$ where previous measurements of its mass using various techniques gave discrepant results. We present a new detailed measurement of the mass with the data based on X-ray observations with the…

Astrophysics · Physics 2009-11-10 K. E. Andersson , G. M. Madejski

We analyze the presence of substructures in a set of 48 galaxy clusters, by using galaxy positions and redshifts. We use a multi-scale analysis which couples kinematical estimators with the wavelet transform. 14% of our clusters are…

Astrophysics · Physics 2007-05-23 M. Girardi , E. Escalera , D. Fadda , G. Giuricin , F. Mardirossian , M. Mezzetti

We present a refinement of the wavelet analysis technique for the detection and characterisation of small scale features embedded in a strongly varying background. This technique handles with particular care the side effects of…

Astrophysics · Physics 2007-05-23 D. Lazzati , S. Campana , P. Rosati , G. Chincarini , R. Giacconi

We use large cosmological N-body simulations to study the subhalo population in galaxy group sized halos. In particular, we look for fossil group candidates with typical masses ~10-25% of Virgo cluster but with an order of magnitude less…

Astrophysics · Physics 2007-05-23 E. D'Onghia , A. V. Maccio' , G. Lake , J. Stadel , B. Moore

To investigate the dynamics of the galaxy cluster A2142, we compile an extended catalog of 2239 spectroscopic redshifts of sources, including newly measured 237 redshifts, within 30 arcmin from the cluster center. With the $\sigma$-plateau…

Astrophysics of Galaxies · Physics 2018-08-22 Ang Liu , Heng Yu , Antonaldo Diaferio , Paolo Tozzi , Ho Seong Hwang , Keiichi Umetsu , Nobuhiro Okabe , Li-Lan Yang

We present a Chandra observation of the merging cluster of galaxies Abell 2744. The cluster shows strong evidence for an ongoing major merger which we believe to be responsible for the radio halo. X-ray emission and temperature maps of the…

Astrophysics · Physics 2009-11-10 Joshua C. Kempner , Laurence P. David

In this study, we investigate a recent finding based on strong lensing observations, which suggests that the sub-halos observed in clusters exhibit greater compactness compared to those predicted by $\Lambda$CDM simulations. To address this…

Filaments of the cosmic web have long been associated with the threadlike structures seen in galaxy redshift surveys. However, despite their baryon content being dominated by hot gas, these filaments have been an elusive target for X-ray…

While there are many ways to identify substructures in galaxy clusters using different wavelengths, each technique has its own caveat. In this paper, we conduct a detailed substructure search and dynamical state characterisation of Abell…

We present high-resolution mass reconstructions for five massive cluster-lenses spanning a redshift range from $z = 0.18$--0.57 utilising archival {\it Hubble Space Telescope} ({\it HST}) data and applying galaxy-galaxy lensing techniques.…

Astrophysics · Physics 2008-11-26 Priyamvada Natarajan , Gabriella De Lucia , Volker Springel

We study the substructure statistics of a representative sample of galaxy clusters by means of two currently popular substructure characterisation methods, power ratios and centroid shifts. We use the 31 clusters from the REXCESS sample,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 H. Boehringer , G. W. Pratt , M. Arnaud , S. Borgani , J. H. Croston , T. J. Ponman , S. Ameglio , R. F. Temple , K. Dolag

We report the discovery that substructures/subhaloes of a galaxy-size halo tend to fall in together in groups in cosmological simulations, something that may explain the oddity of the MW satellite distribution. The original clustering at…

Astrophysics · Physics 2015-05-13 Yang-Shyang Li , Amina Helmi

The XXL Survey is the largest homogeneous and contiguous survey carried out with XMM-Newton. Covering an area of 50 square degrees distributed over two fields, it primarily investigates the large-scale structures of the Universe using the…

For the last 30 years many observational and theoretical evidences have shown that galaxy clusters are not spherical objects, and that their shape is much better described by a triaxial geometry. With the advent of multi-wavelength data of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Mario Bonamigo , Giulia Despali , Marceau Limousin , Raul Angulo , Carlo Giocoli , Geneviève Soucail

We present a new weak lensing analysis of the Hubble Frontier Fields galaxy cluster Abell 2744 ($z$ = 0.308) using new Magellan/MegaCam multi-band $gri$ imaging data. We carry out our study by applying brand-new PSF and shape measurement…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-14 Davide Abriola , Daniele Della Pergola , Marco Lombardi , Pietro Bergamini , Mario Nonino , Claudio Grillo , Piero Rosati

We develop and implement a model to analyze the internal kinematics of galaxy clusters that may contain subpopulations of galaxies that do not independently trace the cluster potential. The model allows for substructures within the cluster…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-25 Evan Tucker , Matthew G. Walker , Mario Mateo , Edward W. Olszewski , Alex Geringer-Sameth , Christopher J. Miller

We explore the internal dynamics of Abell 2254, which has been shown to host a very clumpy and irregular radio halo. Our analysis is mainly based on redshift data for 128 galaxies acquired at the TNG. We also use new g',r',i' photometric…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 M. Girardi , S. Bardelli , R. Barrena , W. Boschin , F. Gastaldello , M. Nonino

We map the lensing-inferred substructure in the first three clusters observed by the Hubble Space Telescope Frontier Fields Initiative (HSTFF): Abell 2744 (z = 0.308), MACSJ0416, (z = 0.396) and MACSJ1149 (z = 0.543). Statistically…

We present evidence for the existence of significant substructure in the cold front cluster Abell 3667 based on multi-object spectroscopy taken with the 3.9m Anglo Australian Telescope. This paper is the second in a series analyzing the…

Astrophysics · Physics 2011-02-11 Matt S. Owers , Warrick J. Couch , Paul E. J. Nulsen