... 1) Studying distributions of stars of different ages in irregular and spiral galaxies we found for each galaxy a clear correlation between the age of stars and the spatial size of the subsystems of stars of this age. ... We made a stellar photometry of eight NGC 1313 fields and of its dwarf companion AM 0319-662 and studied the visible distribution of stars of different ages and of metallicity in the galaxy. ... This disappeared galaxy was the cause of the gravitational deformation of NGC 1313. ...

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). ...

... Abell 2744: Pandoras Cluster of Galaxies . ... Credit Copyright: NASA , ESA , J. Merten ( ITA , AOB ), D. Coe ( STScI ) Explanation: Why is this cluster of galaxies so jumbled? Far from a smooth distribution, Abell 2744 not only has knots of galaxies, but the X-ray emitting hot gas (colored red) in the cluster appears distributed differently than the dark matter . ... Publications with keywords: galaxy cluster - dark matter - hot gas . ... The Hydra Cluster of Galaxies . ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2011 June 29 . Abell 2744: Pandora's Cluster of Galaxies . Image Credit: NASA , ESA , J. Merten ( ITA , AOB ), D. Coe ( STScI ) . ... Far from a smooth distribution, Abell 2744 not only has knots of galaxies, but the X-ray emitting hot gas (colored red) in the cluster appears distributed differently than the dark matter . ... About APOD | ...

... 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? ...

... 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. ...

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. ...

... 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. ...

Wide Field Camera 3: The SOC Science Program Proposal Text An extraordinary panchromatic survey efficiency covering a critical decade of frequency space combined Theme I: Star Formation at Half the Hubble Ti Star Formation at Half the Hubble Tim The Big Questions What determined the properties that galaxies have today? What set the balance between star formation and galaxy as How did feedback shape the galaxy mass function? ... What triggers & regulates star formation? ...

... The obtained results lead to the following conclusions: a) the heavy element enrichment had taken place in the Galaxy in a few bursts of its activity rether than in a continuons manner; b) these bursts occured during the callapse of the early Galaxy; c) the star formation had been inhibited in the time of the bursts; d) the metal enrichment did not proceed in the periods of star formation, between these bursts of activity. ...

... December 13, 1997 . The Coma Cluster of Galaxies . ... The Coma Cluster of Galaxies pictured is one of the densest clusters known - it contains thousands of galaxies . Each of these galaxies house billions of stars - just as our own Milky Way Galaxy does. ... In fact, the Coma Cluster is so big it takes light millions of years just to go from one side to the other! Most galaxies in Coma and other clusters are ellipticals , while most galaxies outside of clusters are spirals . ...