Related papers: Structural Parameters of the Globular Cluster M 15
The globular cluster (GC) M15 (NGC 7078) is host to at least eight pulsars and two low mass X-ray binaries (LMXBs) one of which is also visible in the radio regime. Here we present the results of a multi-epoch global very long baseline…
We present a detailed comparison between the latest observational data on the kinematical structure of the core of M15, obtained with the Hubble STIS and WFPC2 instruments, and the results of dynamical simulations carried out using the…
We present $V$ and $I$ photometry for $\sim 150$ globular clusters with $20 < V < 27$ $\sim 2.5$ arcmin from the centre of M87, the cD galaxy in the Virgo cluster. The data were acquired with the Hubble Space Telescope which, with effective…
We estimate the distribution of intrinsic shapes of APM galaxy clusters from the distribution of their apparent shapes. We measure the projected cluster ellipticities using two alternative methods. The first method is based on moments of…
We consider a sample of 22 nearby clusters of galaxies observed with the Medium Energy Concentrator Spectrometer (MECS) on board of BeppoSAX. They cover the range in gas temperature between 3 and 10 keV, with bolometric X-ray luminosity…
The intrinsic shape of galaxy clusters can be obtained through a combination of X-ray and Sunyaev-Zeldovich effect observations once cosmological parameters are assumed to be known. In this paper we discuss the feasibility of modelling…
We report the detection of the lens cluster of the gravitational lens (GL) system Q0957+561 from a deep observation with the Advanced CCD Imaging Spectrometer on-board the Chandra X-ray Observatory. Intracluster X-ray emission is found to…
Based on an almost complete sample of Galactic open star clusters within 1.8 kpc, we perform a comprehensive statistical analysis of various cluster parameters like spatial position, age, size, mass and extinction in order to understand the…
Based on ROSAT PSPC pointed observations, we have determined the aggregate X-ray shapes of 10 distant (z = 0.17-0.54) rich clusters: A2397, A222, A520, A1689, A223B, A1758, A2218, A2111, A2125, and CL0016+16. Four of the clusters have…
We present the results of our detailed WFPC2-based photometric study of the globular cluster systems (GCS) of over 60 elliptical and S0 galaxies. Approximately 50\% of the GCSs of ellipticals, and at least 15-20\% of S0s reveal bimodality…
Simulations of cluster formation have demonstrated that condensation of baryons into central galaxies during cluster formation can drive the shape of the gas distribution in galaxy clusters significantly rounder, even at radii as large as…
Following a number of conflicting studies of M87's mass profile, we undertake a dynamical analysis of multiple tracer populations to constrain its mass over a large radius range. We combine stellar kinematics in the central regions with the…
We have determined the cluster X-ray temperature function from two flux- and redshift-limited samples of clusters. The first sample is comprised of 25 clusters with average redshift 0.05. The local temperature function derived from it…
We determine the dynamical distance D, inclination i, mass-to-light ratio M/L and the intrinsic orbital structure of the globular cluster omega Cen, by fitting axisymmetric dynamical models to the ground-based proper motions of van Leeuwen…
Previous studies of the galaxy and galaxy cluster distribution in the local Universe found indications for a large extension of the Local Supercluster up to a radius of 190 h_70^-1 Mpc. We are using our large and highly complete CLASSIX…
In this paper we present and analyze new CCD $UBVRI$ photometry down to $V\approx$21 in the region of the young open cluster Trumpler~15, located in the Carina spiral feature. The cluster is rather compact and has a core radius of about…
We test the assumption of strict hydrostatic equilibrium in galaxy cluster MS2137.3-2353 (MS 2137) using the latest CHANDRA X-ray observations and results from a combined strong and weak lensing analysis based on optical observations. We…
We provide novel constraints on the parameters defining the universal pressure profile (UPP) within clusters of galaxies, and explore their dependence on the cluster mass and redshift, from measurements of Sunyaev-Zel'dovich Compton-$y$…
We reanalyze the strong lens modeling of the cluster of galaxies MS2137-23 using a new data set obtained with the ESO VLT. We found the photometric redshifts of the two main arc systems are both at z=1.6. After subtraction of the central cD…
This paper presents CCD multicolour photometry for the old open cluster NGC 188. The observations were carried out as a part of the Beijing--Arizona--Taiwan--Connecticut Multicolour Sky Survey from 1995 February to 2008 March, using 15…