The HST Large Programme on NGC 6752. III. Detection of the Peak of the
  White Dwarf Luminosity Function
  We report on the white dwarf cooling sequence of the old globular cluster NGC
6752, which is chemically complex and hosts a blue horizontal branch. This is
one of the last globular cluster white dwarf (WD) cooling sequences accessible
to imaging by the Hubble Space Telescope. Our photometry and completeness tests
show that we have reached the peak of the luminosity function of the WD cooling
sequence, at a magnitude m_F606W=29.4+/-0.1, which is consistent with a formal
age of ~14Gyr. This age is also consistent with the age from fits to the
main-sequence turnoff (13-14Gyr), reinforcing our conclusion that we observe
the expected accumulation of white dwarfs along the cooling sequence.
