Stellar Clusters are very useful laboratories for empirically studying stellar evolution. ... All cluster stars are at the same distance . All cluster stars have the same physical age . ... CM diagram Young Cluster In this case we see the Main Sequence fully represented. The blue dots represent massive stars with short main sequence lifetimes. ... Thus, identifying the most massive star which is still on the main sequence is an effective means of determining the age of a stellar cluster. ...

... Harald Ebeling, University of Hawaii . ... Abstract . ... Identifying the host galaxies for optically dark gamma-ray bursts . ... The Architecture of Exoplanetary Systems . ... The proposers use Chandra to obtain precise positions of the GRB, and deep follow-up HST observations to search for the host galaxy. ... The calibration of thsi relation rests on observations of binary systems, primarily eclipsing binaries at masses above 1 M Sun , and primarily astrometric binaries at sub-solar masses. ...

... Science . ... The goal is to bring together two communitities: the one working on star formation (mostly galactic) and the one working on the formation of young massive clusters (mostly extra-galactic). We will link galactic with extra-galactic work, optical/NIR techniques with sub-mm/mm/radio ones, the formation of stars with the one of massive star clusters - observations and theory. ... Coordinated by Marina Rejkuba (abstract) . ... How did star formation proceed in Globular Clusters? ...

... The El Gordo Massive Galaxy Cluster . ... The above image of El Gordo is a composite of a visible light image from the Hubble Space Telescope , an X-ray image from the Chandra Observatory showing the hot gas in pink, and a computer generated map showing the most probable distribution of dark matter in blue, computed from gravitational lens distortions of background galaxies. ... Publications with keywords: galaxy cluster - dark matter . Publications with words: galaxy cluster - dark matter . ...

... 2014 April 22 . The El Gordo Massive Galaxy Cluster . Image Credit: NASA , ESA , J. Jee ( UC Davis ) et al. ... Dubbed "El Gordo", the seven billion light years ( z = 0.87) distant galaxy cluster spans about seven million light years and holds the mass of a million billion Suns. ... That galaxy is actually far in the background and has its image stretched by the gravitational lens action of the massive cluster. Follow APOD on: Facebook , Google Plus , or Twitter . ... About APOD | ...

... The relationship of the mass and the observed galactocentric distance R -- (a), and that of the mass and the total dissipation velocity n taken from Gnedin, Ostriker (1997) -- (b). The dotted line in diagram (a) shows the "cone of survival" according to the paper by Surdin and Arkhipova (1998) . ... The solid line is a regression stright line for the main sequence of clusters, and the dotted line parallel to it separates the sequence of clusters of anomalously small mass shown by open triangles. ...

... 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 ...

This animation shows a galaxy cluster with two mass concentrations (the pink shading indicates the projected mass density) lensing a background field of faint blue galaxies. ... Inside the Einstein ring radius one has radial arcs, and right in the center of the cluster there are demagnified images. The highest magnifications occur at the Einstein ring radius, giving the large tangential arcs. ... Abell 2218 and CL2244-02 are clusters with tangential arcs. ... Tutorial : Part 1 | Part 2 | ...

... Kopylov, A.I., Kopylova, F.G. "Structure of galaxy groups and clusters and measurement of their masses", . ... Kopylova, F.G., Kopylov, A.I. "Peculiar 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 Leo supercluster", . ... Kopylova, F.G., Kopylov, A.I. "Analysis of the properties of clusters of galaxies in the region of the Ursa Major supercluster", . ...

... Posts tagged ?massive data? ... Tags: bimodality , chi-square minimization , Classification , CMD , Estimation , machine learning , massive data , model based , PCA , spectral analysis , spectroscopic , survey , VO . ... Algorithms arXiv Astro Bad AstroStat Bayesian CHASC Cross-Cultural Data Processing Fitting Frequentist Galaxies gamma-ray High-Energy Imaging Jargon Job Languages MC MCMC Meta Methods Misc News Nuggets Objects Optical Physics Quotes Spectral Stars Stat Timing Uncertainty X-ray . ...

... The most powerful and widely used methods to calculate the scattering matrix of a fractal cluster are based on the coupled dipoles methods (e.g. the Discrete Dipole Approximation, DDA) and the theory of light scattering by a cluster of spherical particles [2-4]. ... At present the procedure of calculation of the scattering matrix is well developed for both an oriented cluster of spherical particles and for chaotically oriented clusters of such particles [4]. ...

The IMF and Star Formation History of the Stellar Clusters in the Vela D Cloud . ... 2005, A , in press . ... M.T. Beltran, J. Brand, R. Cesaroni, F. Fontani, S. Pezzuto, L. Testi, S. Molinari . ... 2005, Proceedings of the IAUS227 "Massive Star Birth: A Crossroads of Astrophysics", in press . ... Francesco Palla . ... Podio, L., Bacciotti, F., Nisini, B., Giannini, T., Massi, F., Eisloeffel, J., Ray, T.P. 2005, Ap Lecture Series, "Cores to Clusters", in press . ... Star Formation Group . ...

... Observing . ... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... Sky Events . ... A clash of clusters . This collision provides another clue to dark matter. ... Like its famous cousin, the so-called Bullet Cluster, this clash of clusters provides striking evidence for dark matter and insight into its properties. Like the Bullet Cluster, this newly studied cluster, officially known as MACSJ0025.4-1222, shows a clear separation between dark and ordinary matter. ...

... 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. ...

A Canadian and American team of Astronomers have used the 305-m wide Arecibo radio dish, the world's largest and most sensitive radio telescope, to uncover a dozen new super-fast-spinning pulsars. The team directed their search for these rare and exotic stars by pointing the Arecibo radio telescope towards massive star clusters, called Globular Clusters, orbiting our Milky Way galaxy. ... One of the most exotic residents in the Globular cluster system are the millisecond pulsars. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Milky Way . Stars . ... This dramatic image depicts Omega Centauri, one of 200 or so globular clusters orbiting our Milky Way galaxy. ... Swarms of tightly packed stars, numbering in the thousands to low millions, globular clusters are cosmic fossils, relics of the early times of our galaxy. Omega Centauri may actually be the core of a smaller galaxy ripped apart and assimilated by our own Milky Way in the distant past. ...

home publications > mercury . ... Big Clusters, Tiny Galaxies . ... Astronomers struggle to understand why giant star clusters form in the tiniest of galaxies . ... These clusters are probably young versions of globular clusters, but they are commonly called super star clusters. Seven dwarf galaxies within 16 million light-years have formed super star clusters, with one of these galaxies, NGC 1569, possessing two young clusters. ... Super star clusters have a lot to tell us about star formation. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... The projected distance of VFTS 682 to the cluster R136 is 29 pc (for an assumed LMC distance of 50 kpc). ... VFTS 682 is located in an active star-forming region, at a projected distance of 29 pc from the young massive cluster R136 in the Tarantula Nebula of the Large Magellanic Cloud. ... Our aim is to obtain the stellar properties, such as its intrinsic luminosity, and to investigate the origin of VFTS 682. ...

... LMC Project Outline . NGC 1818 Initial Results . ... The Large Magellanic Cloud (LMC) is uniquely suitable for the study of massive star clusters at all stages of evolution. By combining HST observations of these clusters with N-body models we hope to understand the origin and evolution of rich star clusters in our own Galaxy, in the LMC, and beyond. ... We aim to combine our HST observations with N-body models to understand the formation and evolution of globular clusters. ...

... GSAOI Home . ... Science . ... Deep imaging at J , H , and K is required to identify all stellar objects, brown dwarfs, and planetary mass objects in the central region of the Orion Nebula Cluster down to masses comparable to that of Jupiter. This is required to establish the initial mass function, i.e., the number of stars of each mass that have formed, in this region of intense massive star formation. ... The fields of the GSAOI detectors are shown as four green squares in each frame. ...