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). ...

. N OTE: . Only clusters with R<60 kpc were used to compute the spatial parameters and metallicity gradients for all subsystems except the corona. The numbers in parantheses give the number of clusters for which the corresponding parameter is known. The X O scale length of the old halo is strongly distorted by the observed asymmetry of the distribution of the corresponding clusters projected onto the XY plane ( Fig. 4А ) . discussion in the text | previous table .

... 145Slee,Roy Savage We present detailed radio and optical parameters for the stronger radio sources in 58 Abell cluster fields observed with the Very Large Array (VLA) using scaled arrays at 1.5 and 4.9 GHz. ... The cluster fields were distributed over 24 h of RA and between declinations +35 deg and -30 deg. ... Optical identifications Cluster Source Radio Centroid Optical Position EF Ang. ...

... Scientific Objectives of CLASH: . By observing 25 massive galaxy clusters with HST's panchromatic imaging capabilities (Wide-field Camera 3, WFC3, and the Advanced Camera for Surveys, ACS), CLASH accomplishes its four primary science goals: . ... The CLASH program has observed these 25 clusters over a 2.7 year period (Nov 2010 - July 2013). ... The CLASH program observed the clusters with the Advanced Camera for Surveys (ACS) and both the UVIS and IR channels of the Wide-Field Camera 3 (WFC3). ...

Here you can see an image of the central part of the Fornax Cluster taken from the Digital Sky Survey. ... We studied the globular cluster systems (GCSs) of 5 early type galaxies in the Fornax cluster: NGC 1374, NGC1379, NGC 1387, NGC 1427, and the central giant elliptical NGC 1399. ... See our papers ``The central region of the Fornax cluster - I. A catalog and photometric properties of galaxies in selected CCD fields'' and ``The central region of the Fornax cluster - II. ...

... Australia Telescope Compact Array . ... Compact Stellar Systems in the Fornax Cluster: Super-massive Star Clusters or Extremely Compact Dwarf Galaxies? ... We suggest that these objects are either super-massive star clusters (intra-cluster globular clusters or tidally stripped nuclei of dwarf galaxies) or a new type of low-luminosity compact elliptical dwarf (``M32-type'') galaxy. ... Keywords: galaxies: star clusters -- galaxies: dwarf -- galaxies: formation . ... Properties of the compact objects ...

... 2.3 Establishing the Extragalactic Distance Scale . ... 2.3.2 The Second Rung: Distances to stellar clusters . ... 2.3.4 Distances to Local Group Galaxies . ... The Luminosity Function of Planetary Nebulae . ... 3.2.2 Clusters of Galaxies . ... 4.2 Evidence for Dark Matter as a Function of Scale Size . ... 4.3 Other Dark Matter Indicators for Galaxies . ... What is the nature of the large-scale distribution of matter in the universe as traced by the three-dimensional galaxy distribution? ...

... About ATMoB . ... The Observing Committee is starting an Observing Awards Program to promote observing among the membership of the Amateur Telescope Makers of Boston. ... Participant must be a current member of the Amateur Telescope Makers of Boston . ... To qualify for your Observing Award Certificate, turn in your worksheet and drawings to an ATMoB Observing Committee member or observing@atmob.org . ... This Excel sheet has useful macros. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

... 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. ...

... Finding Dark Matter . ... Where is dark matter? Galaxies rotate and move in clusters as if a tremendous amount of unseen matter is present. ... Where do the most massive stars form? ... Visible in the image center are massive stars in the open cluster. ... Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s. Ganymede: Torn Comet Crater Chain . ... Stars, like bees, swarm around the center of bright globular cluster M15. ... First page ] Prev. ...

This collage shows images of six different galaxy clusters taken with NASA's Hubble Space Telescope and Chandra X-ray Observatory. The clusters were observed in a study of how dark matter in clusters of galaxies behaves when the clusters collide. ... Using visible-light images from Hubble, the team was able to map the post-collision distribution of stars and also of the dark matter (colored in blue), which was traced through its gravitational lensing effects on background light. ...

Today's APOD | ... Galaxies rotate and move in clusters as if a tremendous amount of unseen matter is present. ... Specifically, present analyses of above WMAP all-sky image indicate that the universe is 13.7 billion years old (accurate to 1 percent), composed of 73 percent dark energy , 23 percent cold dark matter , and only 4 percent atoms , is currently expanding at the rate of 71 km/sec/ Mpc (accurate to 5 percent), underwent episodes of rapid expansion called inflation , and will expand forever . ...

Next: Rotation Periods of PMS Stars Previous: Direct Monitoring of PMS Stars . Studies using direct detection of periods via rotational modulation have been carried out on stars in several young clusters which are near the zero--age main sequence (ZAMS), including the Hyades, the Pleiades and Persei (see Radick 1988, Schaller et al . ... Rotation in ZAMS clusters has a strong mass dependence. High--mass stars tend to rotate much more quickly than the low--mass stars. ...

... Compact Binaries . ... Globular Clusters . ... Ultra-Compact binaries in globular clusters . ... It is known that UC X-ray binaries are more abundant in globular clusters compared to that found in Galactic fields (eg van der Sluys, Verbunt \ Pols 2005 and references therein). On the other hand no AM CVn systems have been found in globular clusters, while 20 are known in the Galactic field (for a review of AM CVn systems see Nelemans 2005). ...

IFP gallery SCORPIO (since 2000). Here some data observed on the 6m telescope with IFP installed in the SCORPIO focal reducer are presented. ... Velocity field . Mkn 1157 was observed 1 Sep. 2002 in the Ha emission line. Texp =32x240 sec, seeing 1.5", IFP260. ... This galaxy was observed September, 23 2000 in the Ha emission line, Texp=32x120 sec, seeing 2.5", IFP260. ... PV Cep was observed at the 6m telescope in May, 25 2003 in the [SII] 6716A with IFP501, Texp=36x200 sec, seeing 1.0". ...

. Fractal Matter Distribution . Observed fractal galaxy distribution is discuused in: . F.Sylos Labini, M.Montuori L.Pietronero, "Scale invariance of galaxy clustering" astro-ph/9711073 . The home page of "The Debate on fractal Universe"

Astronotes Armagh Planetarium's Stellar Blog! ... Comets and Asteroids . ... Image credit:ESO/J.Emerson/VISTA. ... However others are less pessimistic and it has even been claimed that the mysterious ?Wow! signal? received in 1977 originated from the direction M55.б  Sadly, this still unexplained pulse of radio energy originated from a location rather to the northwest of M55 so I doubt if the source was this cluster (if indeed the signal was genuinely of extraterrestrial origin). ... Mysterious Wow! ...

... 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 ...

... Bisnovatyi-Kogan, Gennady S.; Merafina , Marco; Vaccarelli , Maria Rosaria; Spherically Symmetric Stellar Clusters with Anisotropy and Cutoff Energy in Momentum Distribution. ... We construct numerical models of spherically symmetric Newtonian stellar clusters with anisotropic distribution functions. ... Models of spherically symmetric relativistic stellar clusters with anisotropic distribution functions in relativistic regime are described by using Maxwellian distribution function with energy...

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. ...