... We have made observations of the Perseus cluster with the Westerbork Telescope at 610 MHz. ... Several newly detected sources are identified with cluster galaxies. ... No evidence is found for the existence of the previously reported ~ 65'x25' cluster halo, 3C 84B. Key words: radio galaxies - clusters - tailed radio sources buoyancy The Perseus Cluster of galaxies is one of the most fascinating systems accessible to extragalactic astronomers. ...

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? ...

... Authors: Arunav Kundu 1,2 , Bradley C. Whitmore 1 Using the WFPC2 on-board the HST we have identified 144 globular cluster candidates in the inner region of the S0 galaxy NGC 3115. The color distribution of the globular clusters is bimodal, with a blue peak at V-I = 0.96 mag and a red peak at V-I = 1.17 mag. ... While the red clusters follow the thick disk component of the galaxy, the blue cluster distribution is less flattened and mimics the bulge/halo light distribution. ... huizinga@stsci.edu . ...

... 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. ...

... 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. ...

... 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...

... 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 . ...

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. ...