The Discovery of More than 2000 White Dwarfs in the Globular Cluster ω Centauri

Prada Moroni, P. G.; Pulone, L.; Stetson, P. B.; Bono, G.; Monelli, M.; Buonanno, R.; Corsi, C. E.; Ferraro, I.; Iannicola, G.; Castellani, V.; Calamida, A.; Freyhammer, L. M.

Italy, Belgium, Canada

Abstract

We present deep multiband (F435W, F625W, and F658N) photometric data of the globular cluster ω Cen collected with the Advanced Camera for Surveys on board the Hubble Space Telescope. We identified in the (F435W - F625W, F435W)-plane more than 2000 white dwarf (WD) candidates using three out of nine available pointings. Such a large sample appears to be in agreement with predictions based on the ratio between WD and horizontal-branch evolutionary lifetimes. We also detected ~1600 WDs in the (F658N - F625W, F625W)-plane, supporting the evidence that a large fraction of current cluster WDs are Hα-bright.

Based on observations collected with the Advanced Camera for Surveys on board the Hubble Space Telescope.

2005 The Astrophysical Journal
eHST 29