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  • Bellini, G Piotto, +4 authors Momany
  • 2009
Aims. We present a detailed study of the radial distribution of the multiple populations identified in the Galactic globular cluster ω Cen. Methods. We used both space-based images (ACS/WFC and WFPC2) and ground-based images (FORS1@VLT and WFI@2.2m ESO telescopes) to map the cluster from the inner core to the outskirts (∼20 arcmin). These data sets have(More)
We have examined the radial distribution of white dwarfs over a single HST/ACS field in the nearby globular cluster NGC 6397. In relaxed populations , such as in a globular cluster, stellar velocity dispersion, and hence radial distribution, is directly dependent on stellar masses. The progenitors of very young cluster white dwarfs had a mass of ∼ 0.8 M ⊙ ,(More)
From deep color–magnitude arrays made from V and I images taken with Hubble Space Telescope's WFPC2 camera we have determined luminosity functions (LFs) down to a level that corresponds to ∼0.13 M ⊙ , for the low-metal-abundance globular clusters M15, M30, M92, and NGC 6397. Because of the similarity of the metallicities of these clusters, differences in(More)
We present the results of a deep Hubble Space Telescope (HST) exposure of the nearby glob-ular cluster NGC 6397, focussing attention on the cluster's white dwarf cooling sequence. This sequence is shown to extend over 5 magnitudes in depth, with an apparent cutoff at magnitude F 814W ∼ 27.6. We demonstrate, using both artificial star tests and the(More)
In the old, populous, and metal-rich open cluster NGC 6791 we have used deep HST/ACS images to track the white dwarf cooling sequence down to m F606W ≃ 28.5. The white dwarf luminosity function shows a well defined peak at m F606W ≃ 27.4, and a bending to the blue in the color–magnitude diagram. If this peak corresponds to the end of the white dwarf cooling(More)