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相关论文: Improving Hickson-like compact group finders in re…

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We use various samples of compact groups (CGs) to examine the types of association CGs have with rich and poor clusters of galaxies at low (z~0.04) and intermediate (z~0.1) redshifts. We find that ~10-20 % of CGs are associated with rich…

天体物理学 · 物理学 2015-06-24 H. Andernach , R. Coziol

We investigate the use of the cross-correlation between galaxies and galaxy groups to measure redshift-space distortions (RSD) and thus probe the growth rate of cosmological structure. This is compared to the classical approach based on…

宇宙学与河外天体物理 · 物理学 2016-03-24 Faizan G. Mohammad , Sylvain de la Torre , Davide Bianchi , Luigi Guzzo , John A. Peacock

This is the first in a series of papers on the weak lensing effect caused by clusters of galaxies in Sloan Digital Sky Survey. The photometrically selected cluster sample, known as MaxBCG, includes ~130,000 objects between redshift 0.1 and…

We present a new non-parametric method to quantify morphologies of galaxies based on a particular family of learning machines called support vector machines. The method, that can be seen as a generalization of the classical CAS…

天体物理学 · 物理学 2009-11-13 M. Huertas-Company , D. Rouan , L. Tasca , G. Soucail , O. Le Fevre

The Millennium N-body simulation and the Sloan Digital Sky Survey seventh data release (SDSS DR7) galaxy and galaxy group catalogues are compared to study the properties of galaxy groups and the distribution of galaxies in groups. We…

宇宙学与河外天体物理 · 物理学 2013-10-29 P. Nurmi , P. Heinämäki , T. Sepp , E. Tago , E. Saar , M. Gramann , M. Einasto , E. Tempel , J. Einasto

Nearby Compact Groups of Galaxies (CGs) are very complex systems, tracing their history is a challenge (e.g. Stephan's Quintet). The presence of a diffuse X-rays emission that often peaks in the center of CGs shows that CGs are bound…

天体物理学 · 物理学 2007-05-23 Philippe Amram , Chantal Balkowski , Claudia Mendes de Oliveira , Henri Plana , Benoit Epinat

We present deep H{\alpha} imaging of seven Hickson Compact Groups (HCGs) using the 4.1m Southern Astrophysics Research (SOAR) Telescope. The high spatial resolution of the observations allow us to study both the integrated star-formation…

星系天体物理 · 物理学 2015-05-08 Paul Eigenthaler , Sylvia Ploeckinger , Miguel Verdugo , Bodo Ziegler

We present a weak lensing analysis of a sample of SDSS Compact Groups (CGs). Using the measured radial density contrast profile, we derive the average masses under the assumption of spherical symmetry, obtaining a velocity dispersion for…

星系天体物理 · 物理学 2017-02-03 Martín Chalela , Elizabeth Johana Gonzalez , Diego Garcia Lambas , Gael Foëx

Wide-field optical imaging surveys are efficient at identifying galaxy clusters, but optically identified clusters suffer from projection effects--physically unassociated galaxies along the line of sight can be misidentified as cluster…

宇宙学与河外天体物理 · 物理学 2026-04-02 Lei Yang , Hao-Yi Wu , Tesla Jeltema , Chun-Hao To , Ross Cawthon , Shulei Cao

We investigate the power of the caustic technique for identifying substructures of galaxy clusters from optical redshift data alone. The caustic technique is designed to estimate the mass profile of galaxy clusters to radii well beyond the…

宇宙学与河外天体物理 · 物理学 2015-09-09 Heng Yu , Ana Laura Serra , Antonaldo Diaferio , Marco Baldi

Faint dwarf satellite galaxies are important as tracers of small-scale structure, but remain poorly characterized outside the Local Group, due to the difficulty of identifying them consistently at larger distances. We review a recently…

星系天体物理 · 物理学 2018-06-13 ChengYu Xi , James E. Taylor , Richard J. Massey , Jason Rhodes , Anton Koekemoer , Mara Salvato

We present a new method for quantifying the abundance of satellites around field galaxies and in groups. The method is designed to work with samples, such as local photometric redshift catalogues, that do not have full spectroscopic…

星系天体物理 · 物理学 2021-12-21 Chengyu Xi , James E. Taylor

In this work we present a lensing study of Compact Groups (CGs) using data obtained from the high quality Canada-France-Hawaii Telescope Stripe 82 Survey. Using stacking techniques we obtain the average density contrast profile. We analyse…

Using the photometric redshifts of galaxies from the Sloan Digital Sky Survey III (SDSS-III), we identify 132,684 clusters in the redshift range of 0.05<z<0.8. Monte Carlo simulations show that the false detection rate is less than 6% for…

宇宙学与河外天体物理 · 物理学 2012-05-01 Z. L. Wen , J. L. Han , F. S. Liu

This is the fourth of a series of papers on low X-ray luminosity galaxy clusters. The sample comprises 45 galaxy clusters with X-ray luminosities fainter than 0.7 10$^{44}$ erg s$^{-1}$ at redshifts lower than 0.2 in the regions of the…

星系天体物理 · 物理学 2019-05-17 A. L. O'Mill , M. V. Alonso , C. Valotto , J. L. Nilo Castellón

Compact groups of galaxies are devised as extreme environments where interactions may drive galaxy evolution. In this work, we analysed whether the luminosities of galaxies inhabiting compact groups differ from those of galaxies in loose…

星系天体物理 · 物理学 2022-05-25 Ariel Zandivarez , Eugenia Diaz-Gimenez , Antonela Taverna

Isolated compact groups of galaxies (CGs) present a range of dynamical states, group velocity dispersions, and galaxy morphologies with which to study galaxy evolution, particularly the properties of gas both within the galaxies and in the…

We develop a galaxy cluster finding algorithm based on spectral clustering technique to identify optical counterparts and estimate optical redshifts for X-ray selected cluster candidates. As an application, we run our algorithm on a sample…

星系天体物理 · 物理学 2016-07-15 Eman Mahmoud , Ali Takey , Amin Shoukry

We critically investigate current statistical tests applied to high redshift clusters of galaxies in order to test the standard cosmological model and describe their range of validity. We carefully compare a sample of high-redshift,…

宇宙学与河外天体物理 · 物理学 2015-05-30 Ben Hoyle , Raul Jimenez , Licia Verde , Shaun Hotchkiss