Related papers: Evidence for Merging in the Centaurus Cluster
We have obtained deep photometry of NGC 1199 (in HCG 22) and NGC 6868 (in the Telescopium group). Both galaxies are the optically brightest galaxies of their groups. Our analysis of B and R images taken with the Keck II and the VLT/ESO…
We use deep Chandra X-ray Observatory observations to examine the coronae of the two brightest cluster galaxies in the Coma cluster of galaxies, NGC 4874 and NGC 4889. We find that NGC 4889 hosts a central depression in X-ray surface…
The recent detection of Doppler shifts of X-ray spectral lines in the intracluster gas of the Centaurus and Perseus clusters of galaxies with ASCA has raised the question of the frequency of such velocity gradients and their relation to…
There has been extensive recent progress in X-ray observations of clusters of galaxies with the analysis of the entire ASCA database and recent new results from Beppo-SAX, Chandra, and XMM-Newton. The temperature profiles of most clusters…
We have selected seven medium-distant clusters of galaxies (z ~ 0.1 - 0.3) for multi-wavelength observations with the goal of investigating their dynamical state. Following Paper I (Pierre et al. 1999) which reported the ASCA results about…
Based on a detailed analysis of the high-quality Chandra, XMM-Newton, and Suzaku data of the X-ray bright cluster of galaxies Abell 1795, we report clear evidence for a two-phase intracluster medium (ICM) structure, which consists of a cool…
A new analysis of velocity distribution, optical photometry and X-ray surface brightness from ROSAT PSPC data of the galaxy cluster A 2319 is presented. The temperature profile derived from ASCA data (Markevitch et al.,1996) is taken into…
Wide-field $u'g'r'i'z'$ Dark Energy Camera observations centred on the giant elliptical galaxy NGC5128 covering $\sim21deg^2$ are used to compile a new catalogue of $\sim3200$ globular clusters (GCs). We report 2404 new candidates,…
We present preliminary Chandra results on z=0.2 clusters A665, A2163 and A2218, and a z=0.05 cluster A754. For A754, A665 and A2163, we have derived first high-resolution projected gas temperature maps. All three show strong spatial…
We present a new investigation of the mass-temperature (\MTrelation) relation of 22 nearby clusters based on the analysis of their ROSAT X-ray surface brightness profiles ($S_{X}(r)$) and their ASCA emission weighted temperatures. Two…
We have determined stellar parameters and abundances for 221 giant branch stars in the globular cluster {\omega} Centauri. A combination of photometry and lower-resolution spectroscopy was used to determine temperature, gravity,…
We present here the first analysis of the XMM Newton EPIC-MOS data of the galaxy group around NGC4839, which lies at a projected distance to the Coma cluster center of 1.6Mpc. In our analysis, which includes imaging, spectro-imaging and…
It is well known that the radiative cooling time of the hot X-ray emitting gas in the cores of most clusters of galaxies is less than 10^10 yr. In many clusters the gas temperature also drops towards the centre. If we draw a causal…
We constrain the physical nature of dark matter using the newly identified massive merging galaxy cluster MACSJ0025.4-1222. As was previously shown by the example of the Bullet Cluster (1E0657-56), such systems are ideal laboratories for…
We present Chandra gas temperature maps for two hot, intermediate-redshift clusters A665 and A2163. Both show strong temperature variations in their central r=1 Mpc regions, naturally interpreted as product of the subcluster mergers. The…
We review recent results from Chandra observations of the X-ray bright cores of clusters of galaxies. We discuss the detection of ``cold fronts'' and their implication for thermal conduction, the interaction of cooling flow and radio source…
High resolution, 1.1, 1.6, and 2.2 micron imaging of the luminous infrared galaxy NGC 6090 obtained with NICMOS of the Hubble Space Telescope are presented. These new observations are centered on the two nuclei of the merger, and reveal the…
Although the Perseus cluster has often been regarded as an archetypical relaxed galaxy cluster, several lines of evidence including ancient, large-scale cold fronts, asymmetric plasma morphology, filamentary galaxy distribution, etc.,…
We present new deep photometry of the globular cluster system (GCS) around NGC 6166, the central supergiant galaxy in Abell 2199. HST data from the ACS and WFC3 cameras in F475W, F814W are used to determine the spatial distribution of the…
The Antlia galaxy cluster is the third nearest galaxy cluster after Virgo and Fornax. We used the wide-field MOSAIC camera of the 4-m CTIO telescope to search in the brightest cluster galaxies for globular cluster systems, which were…