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... Explanation: How do you calibrate a huge gravitational lens? In this case the lens is the galaxy cluster Abell 383 , a massive conglomeration of galaxies, hot gas, and dark matter that lies about 2.5 billion light years away ( redshift z=0.187). ... This technique compl e ments other measures including computing the dark matter needed to contain internal galaxy motions , to confine cluster hot gas , and to create the gravitational lens image distortions. ... The Hercules Cluster of Galaxies . ...

... 2014 May 5 . Galaxy Cluster Magnifies Distant Supernova . Image Credit: NASA , ESA , C. McCully ( Rutgers U. ) et al. Explanation: How do you calibrate a huge gravitational lens? ... A new calibration technique has been tested recently that consists of waiting for supernovas of a very specific type to occur behind a galaxy cluster, and then figuring out how much the cluster must have magnified these supernovas through gravitational lensing. ... About APOD | ...

This site provides on-line access to publications, figures, and data tables related to an extensive multi-wavelength observational program to study distant galaxy clusters. ... Lori Lubin, Bev Oke, and Marc Postman have been studying a sample of 9 distant clusters (some taken from the PDCS) using the Keck 10m telescope, the HST, and the KPNO 4m (for IR imaging). ... A Study of Nine High-Redshift Clusters of Galaxies: I. The Survey, . ... A Study of Nine High-Redshift Clusters of Galaxies: II. ...

... Star formation . ... Deep X-ray and IR study of the distant X-ray cluster XDCP J0044.0-2033 (Il Gioiello) at z=1.6 . ... The high redshift cluster XDCP0044 (z=1.6) was discovered in 2011 in the framework of the XMM Distant Cluster Project ( Santos et al. ... These results are published in тАЬ Chandra Deep Observation of XDCP J0044.0-2033, a Massive Galaxy Cluster at z > 1.5 тАЭ , by P. Tozzi et al. ... The cluster is officially known as XDCP J0044.0-2033. ...

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. ...

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 paper ( Burke et al. 2003 ) describes the creation of one such catalogue - the Southern Serendipitous High-redshift Archival ROSAT Cluster (SHARC) survey - which covers an area of 17.7 deg 2 and consists of 32 clusters with redshifts between 0.05 and 0.7 and X-ray luminosities between 7 x 10 42 and 4 x 10 44 erg/s: the high-redshift subsample contains 16 clusters with = 0.3 and X-ray luminosities greater than 2 x 10 43 erg/s (luminosities are quoted for the 0.5 - 2.0 keV energy band). ... 1997 ...

... We found that 10 metal-poor globular clusters are greately distinguished for anomalously small masses on the "destruction rate-mass" plain. As it turned out, these poor clusters, situated 15 kpc farther from the Galactic centre, are somewhat younger than the bulk of the metal-poor globulars, and have anomalously red horizontal branches. ... At the same time, deficiency of distant massive clusters is noticeable with increasing distance from the galactic centre. ...

Galaxy cluster Abell 2218 acts as a powerful lens, magnifying all galaxies lying behind the cluster core. The lensed galaxies are all stretched along the cluster's center and some of them are multiply imaged. ... The color of the lensed galaxies is a function of their distances and types. The orange arc is an elliptical galaxy at moderate redshift (z = 0.7). The blue arcs are star-forming galaxies at intermediate redshift (z = 1-2.5). ...

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! ... 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! ...

... 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. ...

... Structure of Data . ... Catalog . ... In SAI OCL Catalog, we introduce our work on investigation of the Milky Way system of open star clusters. The main goal of our study is a search for new clusters using huge surveys. 168 new clusters have been already discovered by us using J,H,Ks data from 2MASS point source catalog. ... For 141 new clusters, we found their physical parameters using J,H,Ks data from 2MASS catalog and, for a number of clusters, our UBVRI CCD observational magnitudes. ...

... GSAOI Home . ... Science . ... The goal of this project is to detect the termination of the white dwarf cooling sequence in nearby open star clusters, and hence derive cluster ages that are independent of the normal main sequence turnoff method. ... The potential for accurate proper motion measurements, i.e., measurements of transverse motion across the sky, with GSAOI offers a means of overcoming this difficulty. ...

... 1st Announcement IAU Symposium 312 Star Clusters and Black Holes Across Cosmic Time, Beijing, China, Aug. 25-29, 2014 . ... SUBJECT: 1st Announcement IAU Symposium 312 Star Clusters and Black Holes Across Cosmic Time, Beijing, China, Aug. 25-29, 2014 . ... which will be held in Beijing, P.R. China, from August 25-29, 2014, hosted by Chinese Academy of Sciences . ... China), . ... 1st Announcement IAU Symposium 312 Star Clusters and Black Holes Across Cosmic Time, Beijing, China, Aug. ...

... Telescope . ... Images . ... Optical pulsations of Crab pulsar (33 ms period). The optical image of Chandra Galactic ultra deep field (1.5-deg field). Mosaic, pseudocolors are from images in g',r',i' . Full screen (JPG, 0.3Mb) . ... The central part of Coma galaxy cluster. Full screen (JPG, 0.6Мб) . ... The optical image of distant galaxy cluster cl0230+1836 (z=0.80) from 400d X-ray cluster survey . ...

... A Statistical Comparison of Line Strength Variations in Coma and Cluster Galaxies at z 0.3 . ... We present a statistical comparison between spectral line strength variations in Coma galaxies and galaxies in three rich clusters at z 0.3. ... First, more independent parameters are required to account for the line strength variations in the distant cluster data than in the Coma data, and second, line strengths which are not correlated in the distant cluster data are strongly coupled in the Coma data. ...

... Session Chair: . ... Searches for the First Galaxies: Past, Present and Future (Invited) . ... The Hubble Ultra Deep Field 2012: galaxy evolution at z=7-10 . ... Quantifying the Evolution of the Specific Star Formation Rate out to z~7 using Gravitationally Lensed Galaxies from CLASH . ... The role of AGN feedback in the evolution of massive galaxies . ... Evolution in the HI Gas Content of Galaxy Groups: Pre-processing and Mass Assembly in the Current Epoch . ... Gas dynamics in galaxies (Invited) ....

... 87.1083Owen+ VIII/29 1400-MHz Survey of 1478 Abell Clusters of Galaxies (Owen+ 1982) ================================================================================ A 1400-MHz Survey of 1478 Abell Clusters of Galaxies Owen F.N., White R.A., Hilldrup K.C., Hanisch R.J. =1982AJ.. ... 0,] Major axis error 70- 71 A2 --- n_MajAxi *[ A, B, C,NR, ] Major axis note 73- 74 I2 arcmin MinAxi *? ... Note on dist-C: Ratio of the distance of the source from the cluster center to the corrected Abell cluster...