New Hubble Space Telescope WFC3/uvis observations augment the stellar-population complexity of ω Centauri

摘要

We used archival multi-band Hubble Space Telescope observations obtained with the Wide Field Camera 3 in the UV-optical channel to present important new observational findings on the color-magnitude diagram (CMD) of the Galactic globular cluster ω Centauri. The UV WFC3 data have been coupled with available Wide Field Channel/Advanced Camera for Surveys optical-band data. The new CMDs, obtained from the combination of colors coming from eight different bands, disclose an even more complex stellar population than previously identified. This paper discusses the detailed morphology of the CMDs.