Related papers: The Luminosity Function of Omega Centauri
By means of deep FORS1@VLT and ACS@HST observations of a wide area in the stellar system omega Cen we measured the luminosity function of main sequence stars down to R=22.6 and I_{F814W}=24.5 . The luminosity functions obtained have been…
We have investigated the properties of the stellar mass function in the globular cluster NGC6397 using a large set of HST observations that include WFPC2 images in V and I, obtained at ~4' and 10' radial distances, and a series of deep…
Second-epoch HST observations of NGC 6397 have led to the measurement of proper motions accurate enough to separate the faintest cluster stars from the field, thus extending the luminosity function of this globular cluster far enough to…
As part of a large investigation with Hubble Space Telescope to study the faintest stars within the globular cluster Omega Centauri, in this work we present early results on the multiplicity of its main sequence (MS) stars, based on deep…
This paper presents the first study of the most massive globular cluster (GC) in the Milky Way, omega Centauri, employing recently acquired JWST deep images. By combining these data with archival Hubble Space Telescope (HST) images, we…
We report the discovery of an optical counterpart to a quiescent neutron star in the globular cluster Omega Centauri (NGC 5139). The star was found as part of our wide-field imaging study of Omega Cen using the Advanced Camera for Surveys…
We used archival Hubble Space Telescope WFC3 images to obtain the Luminosity Function of the remote globular cluster NGC2419 from two magnitudes above the Horizontal Branch level down to \sim3.0 magnitudes below the Turn Off point (to…
We present a study of the white dwarf (WD) cooling sequence (CS) in the globular cluster (GC) Omega Centauri, the primary goal of a dedicated Hubble Space Telescope (HST) programme. Our analysis has revealed that the peak at the termination…
We summarize results of a search for X-ray-emitting binary stars in the massive globular cluster Omega Centauri (NGC 5139) using Chandra and HST. ACIS-I imaging reveals 180 X-ray sources, of which we estimate that 45-70 are associated with…
We revisit the problem of the split main sequence (MS) of the globular cluster omega Centauri, and report the results of two-epoch Hubble Space Telescope observations of an outer field, for which proper motions give us a pure sample of…
We present HST observations that show a bifurcation of colors in the middle main sequence of the globular cluster Omega Centauri. We see this in three different fields, observed with different cameras and filters. We also present high…
The deepest optical image ever in a globular star cluster, a Hubble Space Telescope (HST) 123 orbit exposure in a single field of Messier 4, was obtained in 2 filters (F606W, F814W) over a 10 week period in early 2001. A somewhat shallower…
From deep color-magnitude arrays made from V and I images taken with the Hubble Space Telescope's WFPC2 camera we have determined luminosity functions (LFs) down to a level that corresponds to about 0.13 solar masses, for the…
We analyze data from the Hubble Space Telescope's Advanced Camera for Surveys of the globular cluster Omega Cen. We construct a photometric and proper-motion catalog using the GO-9442, GO-10252, and GO-10775 data sets. The 2.5- to 4-year…
Omega Centauri ($\omega$ Cen) is the most massive globular cluster of the Milky Way and has been the focus of many studies that reveal the complexity of its stellar populations and kinematics. However, most previous studies have used…
We present an extensive photometry on HB, RGB, and MSTO stars in Omega Cen. The central regions of the cluster were covered with a mosaic of F435W, F625W, and F658N-band data collected with ACS/HST. The outer reaches were covered with a…
The globular cluster omega Centauri contains the largest known population of very hot horizontal branch (HB) stars. We have used the Hubble Space Telescope to obtain a far-UV/optical color-magnitude diagram of three fields in omega Cen. We…
We present a new census of the Orion Nebula Cluster (ONC) over a large field of view (>30'x30'), significantly increasing the known population of stellar and substellar cluster members with precisely determined properties. We develop and…
Omega Centauri is the most massive and chemically complex multi-population globular cluster with a wide metallicity range that has been extensively studied photometrically and spectroscopically. Using the wide metallicity range of omega…
We acquired spectra for a random sample of galaxies within a 0.83 square degree region centered on the core of the Centaurus cluster. Radial velocities were obtained for 225 galaxies to limiting magnitudes of V < 19.5. Of the galaxies for…