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? ...

The radial distribution of metallicity of star-forming galaxies in a galaxy cluster can inform us about the mass assembly and enrichment history of the galaxy cluster. ... Both galaxy clusters are cool-core clusters at redshift z т?? ... The gas-phase metallicity of star- forming galaxies in MACS1115+01 exhibit anti-correlation with projected distance т??0.15 ТБ 0.08 dex/Mpc, whereas the radial metallicity distribution of RXJ1532+30 is statistically flat (т??0.09 ТБ 0.12 dex/Mpc). ...

... The measurements extend to a lower 1.5 GHz limit of 1.0 mJy and comprise a complete sample with 1.5-GHz flux density 2.5 S1.5 J/AuJPh/47/145 VLA Survey of Rich Clusters of Galaxies II (Slee+, 1994) J/AuJPh/49/977 VLA Survey of Rich Clusters of Galaxies III (Slee+, 1996) ================================================================================ A VLA Survey of Rich Clusters of Galaxies II. ... Note (3): An elliptical Gaussian was fitted to the source. ...

... The Hydra Cluster of Galaxies . ... 16.04.2001 . ... Most of a cluster's mass , however, appears to be in a form too dark to see , as analyses of the distribution of X-ray light , gravitational lensing , and internal motions indicate. Abell 1060, as the above cluster is also known, appears to have an even higher fraction of dark matter than seen in a similar cluster, a situation astronomers cannot easily reconcile with both clusters forming solely from gravitational attraction. ... April 2001 . ...

... Editor's choices for the most educational Astronomy Pictures of the Day about clusters of galaxies: . APOD: 2006 March 21 - The Coma Cluster of Galaxies . ... APOD: 2005 November 22 - A Galactic Collision in Cluster Abell 1185 . ... A prominent example occurs on the left of the above image of the rich cluster of galaxies Abell 1185. ... Recent observations of Abell 1185 have found unusual globular clusters of stars that appear to belong only to the galaxy cluster and not to any individual galaxy. ...

... Scientific Objectives of CLASH: . By observing 25 massive galaxy clusters with HST's panchromatic imaging capabilities (Wide-field Camera 3, WFC3, and the Advanced Camera for Surveys, ACS), CLASH accomplishes its four primary science goals: . ... The CLASH program has observed these 25 clusters over a 2.7 year period (Nov 2010 - July 2013). ... The CLASH program observed the clusters with the Advanced Camera for Surveys (ACS) and both the UVIS and IR channels of the Wide-Field Camera 3 (WFC3). ...

... According to the most popular cosmological paradigm, the greater part of the galaxy mass is accumulated in the dark matter halo. ... The polar ring galaxies (PRGs) reveal external rings or disks of gas, dust and stars rotating in a plane roughly perpendicular to the disk of the central galaxy. ... The shape of the dark halo in the model was chosen so as to achieve the best fit to the observed rotation of both galaxies themselves and their polar rings. ... The SPRC-7 galaxy. ...

Here you can see an image of the central part of the Fornax Cluster taken from the Digital Sky Survey. ... We studied the globular cluster systems (GCSs) of 5 early type galaxies in the Fornax cluster: NGC 1374, NGC1379, NGC 1387, NGC 1427, and the central giant elliptical NGC 1399. ... See our papers ``The central region of the Fornax cluster - I. A catalog and photometric properties of galaxies in selected CCD fields'' and ``The central region of the Fornax cluster - II. ...

Formation of intra-group HI gas through multiple galaxy encounters and ram pressure stripping Kenji Bekki (ICRAR at UWA, Australia) (Figures from APOD) Physical processes that drive galaxy evolution in different environments. (a) Ram pressure stripping due to hot intergalactic medium in clusters. ... Ram pressure of warm/hot intra-group gas on extended gaseous (HI) disks of galaxies in small groups and filaments (with Westmeier T. et al. ... 2011) Gas kinematics of disk galaxies under ram pressure. ...

IFP gallery SCORPIO (since 2000). Here some data observed on the 6m telescope with IFP installed in the SCORPIO focal reducer are presented. ... Velocity field . Mkn 1157 was observed 1 Sep. 2002 in the Ha emission line. Texp =32x240 sec, seeing 1.5", IFP260. ... This galaxy was observed September, 23 2000 in the Ha emission line, Texp=32x120 sec, seeing 2.5", IFP260. ... PV Cep was observed at the 6m telescope in May, 25 2003 in the [SII] 6716A with IFP501, Texp=36x200 sec, seeing 1.0". ...

... Observing . ... Subscriber Extras . ... Web Extras . ... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... Observing springtime deep-sky objects with a large telescope . ... Web Extra: Astronomers animate one of the largest galaxy clusters ever observed . ... At the center of the Phoenix Cluster, a large elliptical galaxy lurks where the hot gas is ejected, giving off unprecedented levels of X-rays, which have been observed by the orbiting Chandra X-ray telescope. ...

... About ATMoB . ... The Observing Committee is starting an Observing Awards Program to promote observing among the membership of the Amateur Telescope Makers of Boston. ... Participant must be a current member of the Amateur Telescope Makers of Boston . ... To qualify for your Observing Award Certificate, turn in your worksheet and drawings to an ATMoB Observing Committee member or observing@atmob.org . ... This Excel sheet has useful macros. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

... Abstract: We present Monte Carlo radiative transfer simulations for spiral galaxies modelled as a stellar disk and a two-phase clumpy dust distribution. ... As a general result, clumpy models are less opaque than the corresponding homogeneous models. ... 0.00 0.15 0.50 0.1 0.5 1.0 2.0 5.0 10.0 0.25 X . ... We have also produced several homogeneous models, to compare to the clumpy models. ... Homogeneous and clumpy models with the same tauV have the same dust mass. ...

Next: Transparency of the Stochastic Up: Model of the Galaxy Previous: Frequency distribution of galactic . ... The parameters of the model resulted from a numerical fitting of various data, such as the observed distribution of the young star population and neutral hydrogen, the density of population II stars in the vicinity of the Sun, the galactic rotation curve and the dynamics and distribution of globular clusters   and dwarf irregular satellites of the Galaxy. ...

... Subject and Problems of Stellar Astronomy. ... Plane of Galaxy, Methods of Its Location Determination. ... Stars Distances. ... Other Methods of Stars Distances Determination. ... Tangential Velocities, Their Determination by Self-Motions. ... Determination of Solar Apex and Spatial Velocity by Radial and Spatial Velocities of Stars. ... Features of Orientation and Parameters of Peculiar Stellar Velocities Ellipsoid. ... General and Selective Light Absorption in Galaxy. ... Darc Clouds in Galaxy. ...

... This represents the first HI selected sample covering the core and the outskirts of a local cluster of galaxies. ... Optically selected samples miss a considerable number of low luminosity, low surface brightness galaxies underestimating by almost a factor 2 the number of HI rich galaxies present in the cluster volume. ... Right: The g band luminosity function for galaxies in the A1367 volume as obtained from the optically (circles) and HI (histogram) selected sample. ...

... 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! ...

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. ...

. Fractal Matter Distribution . Observed fractal galaxy distribution is discuused in: . F.Sylos Labini, M.Montuori L.Pietronero, "Scale invariance of galaxy clustering" astro-ph/9711073 . The home page of "The Debate on fractal Universe"

... The study of the Large-scale structure of the Universe and measurements of the Dark Energy equation of state; The exploration of the growth and cosmological evolution of supermassive Black holes in the Universe. ... In course of the all sky survey SRG will discover about 100 000 galaxy clusters and 3 million AGNs. Galaxy clusters are the largest gravitationally bounded objects in the Universe and are best explored through the study of X-ray emission from the hot intergalactic gas. ... 2016 IKI RAN ...