... Archives . ... ArXiv] SVM and galaxy morphological classification, Sept. 10, 2007 . ... On the Metallicity-Color Relations and Bimodal Color Distributions in Extragalactic Globular Cluster Systems by M. Cantiello and J. P. Blakeslee . Many observations on globular cluster systems (GCS) show bimodal distributions in color and metallicity space. ... Based on their simulation study, (V-H) and (V-K) are confirmed to be good colors for revealing unbiased bimodal metallicity distributions in GCS. ...

The radial distribution of metallicity of star-forming galaxies in a galaxy cluster can inform us about the mass assembly and enrichment history of the galaxy cluster. ... Both galaxy clusters are cool-core clusters at redshift z т?? ... The gas-phase metallicity of star- forming galaxies in MACS1115+01 exhibit anti-correlation with projected distance т??0.15 ТБ 0.08 dex/Mpc, whereas the radial metallicity distribution of RXJ1532+30 is statistically flat (т??0.09 ТБ 0.12 dex/Mpc). ...

... Editor's choices for the most educational Astronomy Pictures of the Day about clusters of galaxies: . APOD: 2006 March 21 - The Coma Cluster of Galaxies . ... APOD: 2005 November 22 - A Galactic Collision in Cluster Abell 1185 . ... A prominent example occurs on the left of the above image of the rich cluster of galaxies Abell 1185. ... Recent observations of Abell 1185 have found unusual globular clusters of stars that appear to belong only to the galaxy cluster and not to any individual galaxy. ...

... We have made observations of the Perseus cluster with the Westerbork Telescope at 610 MHz. ... Several newly detected sources are identified with cluster galaxies. ... No evidence is found for the existence of the previously reported ~ 65'x25' cluster halo, 3C 84B. Key words: radio galaxies - clusters - tailed radio sources buoyancy The Perseus Cluster of galaxies is one of the most fascinating systems accessible to extragalactic astronomers. ...

... Resolved Stellar Populations Globular Clusters . Galaxies are made of stars, gas and the illusive dark matter. ... Star clusters are the simplest form of the stellar population. ... Old globular clusters are easily observed at great distances and can be used as probes of the early stages of star formation history in galaxies where individual stars cannot be resolved. My research interests are centered on the studies of resolved stellar populations and (old) star clusters in nearby galaxies. ...

Last time we saw that flat rotation curves for galaxies, when measured in galaxies with extended gas distributions, provides unambiguous data that shows the mass distribution is dominated by an unseen, spherical halo. ... Perhaps only galaxies with extended dark matter halos are capable of retaining large gaseous extents? . ... Clusters of Galaxies: . ... The case of the Cancer cluster: . ... Below is the velocity distribution of galaxies in the Cancer cluster: . ... What's going on in Cancer? ...

... The Hydra Cluster of Galaxies . ... 16.04.2001 . ... Most of a cluster's mass , however, appears to be in a form too dark to see , as analyses of the distribution of X-ray light , gravitational lensing , and internal motions indicate. Abell 1060, as the above cluster is also known, appears to have an even higher fraction of dark matter than seen in a similar cluster, a situation astronomers cannot easily reconcile with both clusters forming solely from gravitational attraction. ... April 2001 . ...

... Authors: Arunav Kundu 1,2 , Bradley C. Whitmore 1 Using the WFPC2 on-board the HST we have identified 144 globular cluster candidates in the inner region of the S0 galaxy NGC 3115. The color distribution of the globular clusters is bimodal, with a blue peak at V-I = 0.96 mag and a red peak at V-I = 1.17 mag. ... While the red clusters follow the thick disk component of the galaxy, the blue cluster distribution is less flattened and mimics the bulge/halo light distribution. ... huizinga@stsci.edu . ...

... Staff . ... Galaxies, AGN, Cosmology . ... A new survey of X-ray clusters of galaxies with the Swift-X-ray Telescope . ... In this framework, an international collaboration between INAF-OAA, INAF-Brera, INAF-OATs, the University for Science and Technology of China-Hefei, the University of Ferrara, and the University of Massachusetts-Amherst, is undertaking a new cluster survey using an X-ray facility that was never exploited before for this goal: the X-ray Telescope (XRT) onboard the Swift satellite...

... Dept. for Physics of Stars&Galaxies . ... Using a database view Sloan Digital Sky Survey (SDSS), containing almost a million spectra created 15,000 sample galaxies with active star formation, which is used for various studies and physical state of evolution of galaxies. ... Star clusters of the Galaxy . The project MWSC (Milky Way Star Clusters) directory using 2MASS, which includes nearly 500 million vision to the limit Ks = 15.3, analyzed more than 4,000 cluster-like objects in the galaxy. ...

Formation of intra-group HI gas through multiple galaxy encounters and ram pressure stripping Kenji Bekki (ICRAR at UWA, Australia) (Figures from APOD) Physical processes that drive galaxy evolution in different environments. (a) Ram pressure stripping due to hot intergalactic medium in clusters. ... Ram pressure of warm/hot intra-group gas on extended gaseous (HI) disks of galaxies in small groups and filaments (with Westmeier T. et al. ... 2011) Gas kinematics of disk galaxies under ram pressure. ...

... Visible Distribution of Galaxies. ... Features of Elliptical, Lens-Shaped, Spiral and Irregular Galaxies. Galaxies with Bar. ... Distribution of Surface Brightness of Surface and Spiral Galaxies. ... Color Characteristics of Galaxies. ... Methods of Galaxies' Mass Determination. ... Hidden Mass of Spiral Galaxies. ... Features of Dark Matter Distribution in E and SO Galaxies. ... The Whole Number of Galaxies and Their Density by the Results of Observation on the 'Hubble' Space Telescope. ...

... The study of the Large-scale structure of the Universe and measurements of the Dark Energy equation of state; The exploration of the growth and cosmological evolution of supermassive Black holes in the Universe. ... In course of the all sky survey SRG will discover about 100 000 galaxy clusters and 3 million AGNs. Galaxy clusters are the largest gravitationally bounded objects in the Universe and are best explored through the study of X-ray emission from the hot intergalactic gas. ... 2016 IKI RAN ...

Authors: V.A. Marsakov , T.V. Borkova , . ... It is shown that general populations of globular clusters and metal-poor field stars are components at least of three subsystems occupying different volumes in the Galaxy. The thick disk and proto-disk subsystems are genetically associated with the Galaxy. ... It is argued that heavy-element enrichment and the collapse of the proto-galactic medium occurred mainly in the period between the formation of the proto-disk halo and thick disk subsystems. ...

... This represents the first HI selected sample covering the core and the outskirts of a local cluster of galaxies. ... Optically selected samples miss a considerable number of low luminosity, low surface brightness galaxies underestimating by almost a factor 2 the number of HI rich galaxies present in the cluster volume. ... Right: The g band luminosity function for galaxies in the A1367 volume as obtained from the optically (circles) and HI (histogram) selected sample. ...

Clusters of Galaxies and Large-Scale Structure ** . ... Kopylov, A. I.; Kopylova, F. G. Structure of galaxy groups and clusters measurment of their masses . ... Kopylova, F. G.; Kopylov, A. I. Pecular motions of galaxy clusters and groups in the Hercules and Leo supercluster regions . ... Kopylova, F. G.; Kopylov, A. I. Analysis of the properties of clusters of galaxies in the region of the Ursa Major supercluste . ... Kopylova, F. G.; Kopylov, A. I. The Ursa Major Supercluster of Galaxies: II. ...

... We address a question if globular clusters (GC) in a protogalaxy could for some time evolve chemically as isolated systems, enriching themselves with heavy elements produced in first supernova events that follow initial star formation. We determine both the critical mass of a protoglobular cluster that is needed to retain the ejecta of the very first supernova, and the critical energy (i.e., number of supernovae) that is needed to expel the residual gas from a cluster of a given mass. ...

The Mass-Density of the Universe and the Distribution of Dark Matter Neta A. Bahcall Princeton University, USA One of the most fundamental questions of cosmology is: How much matter is there in the Universe and how is it distributed? Here we show that several independent measures - including those utilizing clusters of galaxies - all indicate that the mass-density of the Universe is low: only 20-30% of the critical density. ... The results reveal a low den- sity of 0.16+-0.05. ...

Title: A New Model of the Gravitational Lens 0957+561 and a Limit on the Hubble Constant . Authors: Norman A. Grogin , Ramesh Narayan (Harvard Univ.) ... Title: ROSAT/PSPC observation of the distant cluster CL0939+472 . ... Title: Interaction in the Bimodal Galaxy Cluster A3528 . ... Title: Cosmological Implications of Galaxy Cluster Evolution . ... Title: Galaxy Cluster Virial Masses and Omega . ... Matches 201 to 222 from a total of 222 matches for the search pattern galaxy cluster . ...

... Our Milky Way galaxy is host to a number of companions. These companions are gravitationally bound to the Milky Way and are stellar systems in their own right. They include a population of about 150 globular clusters (GCs) and some 30 dwarf satellite galaxies (DSGs). ... These DSGs are more extended and diffuse compared to GCs. In fact the larger satellites of the Milky Way (and other galaxies, for that matter) host their own small systems of GCs. ...