... While imaging the cluster of galaxies Abell 370, astronomers had noted an unusual arc to the right of many cluster galaxies. ... In the mid-1980s, however, better images allowed astronomers to identify the arc as a prototype of a new kind of astrophysical phenomenon -- the gravitational lens effect of entire cluster of galaxies on background galaxies. ... In mid-July, astronomers used the just-upgraded Hubble Space Telescope to image Abell 370 and its gravitational lens images in unprecedented...

... 2009 September 21 . Abell 370: Galaxy Cluster Gravitational Lens . ... While imaging the cluster of galaxies Abell 370, astronomers had noted an unusual arc to the right of many cluster galaxies. ... In the mid-1980s, however, better images allowed astronomers to identify the arc as a prototype of a new kind of astrophysical phenomenon -- the gravitational lens effect of entire cluster of galaxies on background galaxies. ... About APOD | ...

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 . ...

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 . ...

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 | ...

Astronotes Armagh Planetarium's Stellar Blog! ... Stars . ... Starbursts are short-lived events, stars are forming so quickly that the reservoirs of interstellar gas from which stars are coalescing would be used up on a timescale much shorter than the age of the galaxy . ... Strong stellar winds from giant new stars in the starburst region combine with the blasts of supernovae to push a mighty flood of extremely hot gas, a ?superwind? from the galaxy thousands of light years into intergalactic space. ...

... Bad Astronomy . ... Bitesize Astronomy . ... Last week's Snack talked about how black holes can affect the environment around them in such a way as to be very bright . ... It's a common misconception that black holes always have matter swirling into them. ... As this matter gets closer and closer to the black hole it piles up and a large, fairly flat disk forms. This is called the accretion disk , because matter from this disk accretes (that is, falls in) on the black hole. ... 2008 Phil Plait. ...

... 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. ...

... 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 > . ...

... Primordial theory review : Dick Bond . Defects and the CMB review : Andy Albrecht . ... Gravitational wave contribution to CMB anisotropies : V.B. Lukash and E.V. Mikheeva . C_l from cosmic strings : Lloyd Knox . Some aspects of CMB anisotropies induced from topological defects : Mairi Sakellariadou . ... CMB anisotropies from scaling sources : Ruth Durrer . ... SZ observations I : Sarah Church . ... Holes in the microwave sky? ... Detecting cosmic strings in the CMB : James Robinson . ...

... Science . ... Science Users Information > Science Activities > PhD Thesis Topics offered by ESO Faculty Members > Studying the Cosmological Evolution of Galaxy Clusters with (Sub-)mm Observations . ... Data Handling and Products . ... ESO Data . ... Studies of the Planck data set with optical and sub-mm follow-up observations give new insights about the early assembly of the first clusters, and the later evolution of their gas content as well as of their population of star-forming galaxies. ...

... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... A star cluster hides star clusters . ... W hile exploring deep Hubble Space Telescope images of a globular star cluster called NGC 6397, astronomers stumbled on a distant background galaxy harboring hundreds of similar clusters. ... A single giant star in NGC 6397 outshines one of the background galaxy's clusters by 10 million times....

... Archives . ... my first AAS. ... I was questioned by two attendees, acquainted before the AAS, if I can suggest them clustering methods relevant to their projects. ... classification vs. clustering or supervised learning vs. unsupervised learning : the former terms from the pairs indicate the fact that the scientist already knows types of objects in his hands. ... Tags: Classification , clustering , cosmology , spatial statistics , supervised learning , test , unsupervised learning . ...

... 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. ...

In 2001, Westerbork observations of the disturbed galaxy named VV-29 (alias Arp-188, UGC-10214) showed that there is second smaller galaxy (named VV-29c) that appears behind the western side of the main body of the distorted galaxy. ... The galaxy was featured as the May 2, 2002 Astronomy Picture of the Day . ... When VV-29 had its 15 minutes of fame in May 2002, it appeared under the name "The Tadpole Galaxy," but based on the images above, we will always think of it as "The CHAINSAW"! ...

... Our Milky Way galaxy is host to a number of companions. These companions are gravitationally bound to the Milky Way and are stellar systems in their own right. They include a population of about 150 globular clusters (GCs) and some 30 dwarf satellite galaxies (DSGs). ... These DSGs are more extended and diffuse compared to GCs. In fact the larger satellites of the Milky Way (and other galaxies, for that matter) host their own small systems of GCs. ...

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... 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 ...

... Comment specifications may appear in the body of dataset, table and array specifications. There is no limit to the number of comment specifications which may appear in each of the allowed specification bodies. ... comment is the comment designator keyword. This is used to begin a new comment specification. string is the text which comprises the comment. ... This is used to begin a new comment specification. free-format-text is the text which which comprises the comment (delimited by and ). ...

... Confirm Dark Galaxy Existence . ... New evidence from NASA's Hubble Space Telescope and the Westerbork Synthesis Radio Telescope in the Netherlands has been used to rule out all but one of the ideas put forward to explain the existence of VIRGOHI 21, an intergalactic gas cloud 50 million light-years from the Earth. ... Are there more such dark galaxies out there? ... Credit: R. Minchin / Arecibo Observatory / Cardiff University / Isaac Newton Telescope / Westerbork Synthesis Radio Telescope . ...