Related papers: Star counts in NGC 6397
In this letter we present calibrated mass and light profiles of the rich cluster of galaxies Abell 1689 out to 1 $h^{-1}$ Mpc from the center. The high surface density of faint blue galaxies at high redshift, selected by their low surface…
We measure the nitrogen abundance in 5 Turn Off(TO) stars of the Globular Clusters NGC 6397 and NGC 6752, and compare the cluster abundances with those of field stars of comparable metallicity. We determine the nitrogen abundance from the…
We present the first high spatial resolution X-ray study of the massive star forming region NGC 6357, obtained in a 38 ks Chandra/ACIS observation. Inside the brightest constituent of this large HII region complex is the massive open…
A panchromatic view of the star forming ring and feeding process in the central kpc of the galaxy NGC 1097 is presented. The assembled IR to UV images at $\sim$10 pc resolution allow us to characterise the population of circa 250 clusters…
If NGC 6397 contains a large fraction of "second generation" stars (>70% according to recent analysis), the helium abundance of its stars might also be affected, show some star-to-star variation, and be larger than the standard Big Bang…
We present the results of the analysis of deep photometric data of 32 Galactic globular clusters. We analysed 69 parallel field images observed with the Wide Field Channel of the Advanced Camera for Surveys of the Hubble Space Telescope…
We present internal surface-brightness profiles, based on HST/ACS imaging in the F606W bandpass, for 131 globular cluster (GC) candidates with luminosities 10^4 - 3 x 10^6 solar, in the giant elliptical galaxy NGC 5128. Several structural…
We have obtained optical multicolour (UBVRI) linear polarimetric data for 46 of the brightest stars in the area of the open cluster NGC 6124 in order to investigate the properties of the interstellar medium (ISM) that lies along the line of…
Shells in Elliptical Galaxies are faint, sharp-edged features, believed to provide evidence of a recent ($\sim 0.5 - 2 \times 10^9$ years ago) merger event. We analyse the Globular Cluster (GC) systems of six shell elliptical galaxies, to…
Ultra-compact dwarf galaxies (UCDs) share many properties with globular clusters (GCs) and are found in similar environments. A large sample of UCDs and GCs around NGC 1399, the central giant elliptical of the Fornax galaxy cluster, is used…
The average mass density profile measured in the CNOC cluster survey is well described with the analytic form rho(r)=A/[r(r+a_rho)^2], as advocated on the basis on n-body simulations by Navarro, Frenk & White. The predicted core radii are…
We present evidence that some of the compact, luminous, young star clusters recently discovered through images taken with the Hubble Space Telescope (HST) have masses comparable to those of old Galactic globular clusters. The "super star…
The distributions of size and luminosity for star-forming regions in the nearby spiral galaxy NGC 628 are studied over a wide range of scales using progressively blurred versions of an image from the Hubble Space Telescope Advanced Camera…
We study the outer regions of the Milky Way globular cluster NGC 7089 based on new Dark Energy Camera (DECam) observations. The resulting background cleaned stellar density profile reveals the existence of an extended envelope. We confirm…
We present stellar and dark matter (DM) density profiles for a sample of seven massive, relaxed galaxy clusters derived from strong and weak gravitational lensing and resolved stellar kinematic observations within the centrally-located…
We present H-band observations of the elliptical galaxy NGC4696, the brightest member of the Centaurus cluster of galaxies. We have measured its light profile, using a two-dimensional fitting algorithm, out to a radius of 180 arcsec (37…
We present an observational far-UV (FUV) and near-UV (NUV) study of the core region of the globular cluster NGC 6397. The observations were obtained with the Space Telescope Imaging Spectrograph (STIS, FUV), and the Wide Field Camera 3…
The center of the nearby galaxy NGC\,253 hosts a population of more than a dozen super star clusters (SSCs) which are still in the process of forming. The majority of the star formation of the burst is concentrated in these SSCs, and the…
The turnover, or peak, magnitude in a galaxy's globular cluster luminosity function (GCLF) may provide a standard candle for an independent distance estimator. Here we examine the GCLF of the giant elliptical NGC 4365 using photometry of ~…
We present a detailed study of the strengths of the calcium triplet absorption lines in the spectra of a large sample of red giant members of the luminous outer Galactic halo globular cluster NGC 5824. The spectra were obtained with the…