... 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 | ...

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 | ...

... Dark Matter Ring Modeled around Galaxy Cluster CL0024 17 . ... These are multiple images of a few distant galaxies, showing that the cluster is a strong gravitational lens . ... A hypothesis for the formation of the huge dark matter ring holds that it is a transient feature formed when galaxy cluster CL0024+17 collided with another cluster of galaxies about one billion years ago, leaving a ring similar to when a rock is thrown in a pond. ... Abell 2218: A Galaxy Cluster Lens . ...

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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? ...

... Abstract . ... A Survey for Supernovae in Massive High-Redshift Clusters . ... Combined optical and x-ray image of the "Bullet" galaxy cluster: the red outlines the distribution of hot, baryonic gas (from X-rays); the blue maps the underlying (dark matter) mass distribution. ... Galaxy-galaxy lenses, however, offer a distinct advantage, since the background source is extended, and therefore imposes a stronger constraints on the mass distribution of the lensing galaxy than a point-source QSO. ...

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 . ...

... Feeding the Monster: Gas Caught in its Death Spiral into a Massive Black Hole . ... Stromlo Professor Mike Dopita have used the Hubble Space Telescope to discover how a massive Black Hole in a nearby galaxy feeds itself. ... Earlier Hubble Telescope data obtained by another team member, Professor Holland Ford of Johns Hopkins University in Baltimore, Maryland, had found a disk of gas rushing around the Black Hole at a speed of 500 kilometers a second. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Armagh Planetarium . ... Stars . ... Space Flight . ... Monthly Sky Notes . ... By admin October 1, 2010 Posted in: Stars . A sky of blazing stars (Image Credit: NASA/ESA) . Imagine that once the Sun sets, rather than a dark sky sprinkled with a few thousand dim stars, we had a sky blazing with ten thousand or so stars blazing brighter than Venus. ... Planets orbiting stars in the NGC 3603 Young Cluster would experience just such a sky. ...

... The search for distant objects which can be both galaxies and quasars is one of the most important problems of observational astrphysics, because it allows one to determine cosmological parameters connected with the time of appearence and evolution of stellar systems, large scale structure of the Universe. ... Radio galaxies are important objects to be studied because they are sources of infrared-optical-ultraviolet continuum, emission lines and continual radio emission. ...

This multi-wavelength image of Abell 520 shows the aftermath of a complicated collision of galaxy clusters, some of the most massive objects in the universe. ... Optical data from the Canada-France-Hawaii and Subaru telescopes show the starlight from the individual galaxies (yellow and orange). The location of most of the matter in the cluster (blue) was also found using these telescopes, by tracing the subtle light-bending effects on distant galaxies. ... NASA/CXC/CFHT/Univ. ...

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. ...

... The sample of the Local Volume galaxies (distance smaller than 10 Mpc) gives a unique opportunity to study the properties of galaxies including the weakest objects: the absolute magnitude M B -10 and the virial mass M vir 10 9 M x263C;. ... Luminosity function of the Local Volume galaxies. ... The luminosity functions for galaxies are presented: red dashed line - from the 2dFGRS survey (Norberg et al. 2002); blue dash-dotted line - from the SDSS survey (Blanton et al. ...

... ATNF Home . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . Mopra radio telescope . ... Australia Telescope Online Archive (ATOA) . ... Australia Telescope 20GHz Survey . ... Visiting Parkes radio telescope . ... Parkes radio telescope webcam . ... Major mergers provide an important channel for morphology transformation. ...

ESO PR Photo 18b/00 . ... Caption : Images of two of the novae in NGC 1316 that were discovered during the observational programme described in this Press Release. ... In particular, no less than four novae were detected in a single giant galaxy within only 11 days . ... Moreover, the discovery of four novae in one galaxy in the Fornax cluster was possible with only 3 hours of observing time per filter. ... ESO Press Information is available on the WWW at . http://www.eso.org/outreach/press-rel/ . ...

... 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. ...

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. ...

... 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...

Next: SMUDGES Up: Minutes of the 1st Previous: Pilot Survey . ... The Jodrell Virgo survey is part of HIJASS and encompasses 4 X 8 degrees, fully sampled. ... This indicates that we should perhaps survey the outskirts of the cluster to look for low mass clouds. In the survey, objects were detected using a combination of by-eye method and automated routine. 28 detections of well known galaxies . ... Velocity distribution suggests infall or extension along the line of sight. ... Jon . ...

Next: Star Formation Rate and Up: No Title Previous: Calculation of Evolutionary Tracks . To start calculations, we choose the distributions of the initial binary parameters: the mass of the primary ZAMS component, , binary mass ratio, , orbital separation a . ... whereas the mass ratio distribution is not. ... The zero assumption often made is that the mass ratio distribution has a flat shape, that is binaries with a high mass ratio occur as frequently as those with equal masses. ...