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). ...

... Subject and Problems of Stellar Astronomy. ... Plane of Galaxy, Methods of Its Location Determination. ... Stars Distances. ... Other Methods of Stars Distances Determination. ... Tangential Velocities, Their Determination by Self-Motions. ... Determination of Solar Apex and Spatial Velocity by Radial and Spatial Velocities of Stars. ... Features of Orientation and Parameters of Peculiar Stellar Velocities Ellipsoid. ... General and Selective Light Absorption in Galaxy. ... Darc Clouds in Galaxy. ...

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... Here we present our first results of a study of the neutral hydrogen gas (HI) in the southern spiral galaxy NGC 253 with the Australia Telescope Compact Array . ... Several peculiar features have been found. ... Similar features have been found in other starburst galaxies like M82, NGC 1808 and NGC 4945 and are interpreted in terms of bar-induced gas dynamics and star formation. Keywords. galaxies: individual (NGC 253) - galaxies: active - galaxies: ISM - galaxies: kinematics and dynamics. ...

... 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. ...

... 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. ...

... Chandra Observation of DEEP2 Galaxy Groups and Clusters . ... Monday: 'Normal' Galaxies, Tuesday: Cluster Formation and Evolution . ... Statistics of galaxy groups in ultradeep XMM surveys. ... What can multiwavelength observations tell about cluster/group formation as well as galaxy evolution? ... I will present results from a Chandra study of eight low-redshift clusters that has systematically measured the AGN fraction in clusters and describe their spatial, kinematic, and host galaxy...

HST resumed operations on the side B electronics on the CU/SDF (Command Unit/Science Data Formatter) on 23 October 2008. WFPC2 calibration measurements and on-sky observations restarted on October 25th, and the ACS/SBC will be brought on line later this week. ... A Snapshot Survey of The Most Massive Clusters of Galaxies . Abstract . ... Binaries in the Kuiper Belt: Probes of Solar System Formation and Evolution . ... Distances to Eclipsing M Dwarf Binaries . ... Past weeks: . ...

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. ...

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 . ...

Blueshifted galaxies in the Virgo cluster I. D. Karachentsev, O. G. Nasonova (Kashibadze), Special Astrophysical Observatory, Russia We consider a sample of 65 galaxies with negative radial velocities with respect to the Lo cal group in the Virgo cluster. ... E, S0 20 ° The radial velo city VLG ­ magnitude mB distribution of sample ob jects. ... The centroid drift for galaxies ranged by VLG from zero to the extremal negative velo city (-866 km/s). ...