... 2010 June 20 . Abell 2218: A Galaxy Cluster Lens . ... Gravity can bend light, allowing huge clusters of galaxies to act as telescopes, and distorting images of background galaxies into elongated strands. Almost all of the bright objects in this Hubble Space Telescope image are galaxies in the cluster known as Abell 2218. ... The cluster of galaxies Abell 2218 is itself about three billion light-years away in the northern constellation of the Dragon ( Draco ). ... About APOD | ...

... May 3, 1997 . Giant Cluster Bends, Breaks Galaxy Images . ... Explanation : What are those strange blue objects? Many are images of a single, unusual, beaded, blue, ring-like galaxy which just happens to line-up behind a giant cluster of galaxies. ... The distinctive shape of this background galaxy -- which is probably just forming -- has allowed astronomers to deduce that it has separate images at 4, 8, 9 and 10 o'clock, from the center of the cluster. ... About APOD > . ...

... Abell 2218: A Galaxy Cluster Lens . ... Gravity can bend light, allowing huge clusters of galaxies to act as telescopes, and distorting images of background galaxies into elongated strands. Almost all of the bright objects in this Hubble Space Telescope image are galaxies in the cluster known as Abell 2218. ... As a result, multiple images of these background galaxies are distorted into long faint arcs -- a simple lensing effect analogous to viewing distant street lamps through a glass of wine . ...

M1 image More About M1 Nice Color Picture . ... M16 image More About M16 HST image . ... M31 image More About M31 Nice Color Picture . ... M42 image ; M43 image More About M42/43 Nice Color CCD Picture . M51 image More About M51 Color Image of M51 M51 Supernova . M57 image More About M57 Nice Color CCD Picture Very Deep M57 Image . ... M81 image More About M81 M81 Supernova Ultraviolet Image of M81 More about Ultraviolet Imaging . M82 image More About M82 M82 False Color M82 True Color . ...

... Kalirai and Harvey Richer of the University of British Columbia led the study, which began as an investigation of a globular star cluster in the Milky Way galaxy known as NGC 6397. ... Within the population of stars and galaxies behind NGC 6397, the Hubble image revealed a large elliptical galaxy that contains several hundred globular clusters. ... In fact, a single giant star in NGC 6397 appears 10 million times brighter than one of the distant globular clusters. ...

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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! ...

... Research . ... A rare hybrid morphology radio galaxy . ... In this project we will be able to investigate the environmental effect on star formation and galaxy evolution in individual galaxies falling into the cluster through radio observations of active galactic nuclei (AGN). Current models of galaxy evolution regulate the star formation rates within the simulated galaxies by invoking radio-mode feedback from AGN. ... Julie.Banfield@anu.edu.au . ...

In autumn 1994, two groups of astronomers announced that they had discovered Cepheid variable stars in a distant cluster of galaxies. ... As the term suggests, variable stars change in brightness over time. ... Variable stars are an ideal way to get high-school students doing real science, with real data, from the real sky. ... a sky chart to find the stars . ... Students can use the nearby stars to estimate the magnitude of Delta. ... Locate the star Delta in Cepheus and estimate its brightness . ...

... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Facilities . ... CSIRO's newest radio telescope, ASKAP, has opened a window to a little-explored period of the UniverseтАЩs history, by using a special technique to spot a galaxy five billion light-years away. ... An absorption line was detected at z = 0.44 towards the radio source PKS B1740-517, and confirmed by optical spectroscopy to be intrinsic to the early-type host galaxy. ...

... The highest redshift X-ray jet discovered . by Chandra in GB 1428+4217 at z = 4.72 . X-ray jet discovered by Chandra . ... Science Papers on ADS . ... Chandra Press Release . The paper describing the details nas been published in ApJ and it is available also on astro-ph Feb. ... The jet paper published in ApJ Letters is available on astro-ph Oct. ... ApJ Letters paper available on astro-ph: Paper 2003 Feb. ... ApJ papers available on astro-ph: Paper 1, 2002 and Paper 2, 2007 . ...

Astronomers have discovered a massive cluster of young galaxies forming in the distant universe. The growing galactic metropolis, named COSMOS-AzTEC3, is the most distant known massive "proto-cluster" of galaxies, lying about 12.6 billion light-years from Earth. ... The other dots in this picture are stars or galaxies that are not members of the cluster тАФ most of them are located closer to us than the cluster, but some are farther away. The two brightest spots are stars. ...

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 . ...

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. ...

... 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. ...

... Over the first 4 years, its X-ray telescopes eROSITA and ART-XC will survey the whole sky with a record sensitivity in the 0.5-10 keV energy band. ... The goal of the second international Spectrum-RG conference is to discuss the different scientific topics addressed by the mission, synergies with surveys at other wavelengths, and requirements to follow-up observations.Contributed talks and poster presentations are invited on the topics related to the SRG science goals. ... Active galactic nuclei . ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . Portrait of Sir William Herschel (1738-1822) Royal Astronomical Society . Probably the most famous astronomer of the 18th century, Sir William Herschel discovered, in addition to the planet Uranus, many new nebulae, clusters of stars and binary stars. ... Other Herschel Family Portraits . Mirror by Herschel . Return to A Short History of Armagh Observatory . Last Revised: 2009 November 23rd . ...

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 | ...

... Astrophysics Group . ... AMI Science . ... Observations of galaxy clusters are central to the AMI science programme. The AMI Small Array is used to observe already-known clusters with high-sensitivity and resolution, allowing us to extract detailed information about individual clusters and to build up statistics about the cluster population. ... Observing galaxy clusters at 15 GHz is tricky because of the contamination from foreground radio sources, which is where the Large Array comes in! ...

... Our Sun is part of a huge wheel-shaped collection of stars. ... Astronomers have long suspected it was a very massive black hole, and that every galaxy had such a central mass, created early in the history of the universe. ... However, unless that object happens to be headed directly at the black hole (a relatively small target) it will just swing around and fly away again, like a comet making a pass at the Sun. The velocity acquired in falling towards the black hole also helps it escape. ...