In my talk, I want to highlight the unique potential of integral-field
spectroscopy in the study of Galactic globular clusters. While
traditional spectroscopy has revealed many intriguing details about
their nature, such as the existence of multiple populations, it is
limited to observations of the relatively few isolated stars in a
cluster. I will show how the combination of integral field spectroscopy
and deblending techniques known from crowded field photometry can
overcome this limitation and significantly increase the number of
spectroscopically accessible stars.
A science case that particularly benefits from this improvement is the
search for intermediate mass black holes (IMBHs). The existence of these
objects is still a matter of significant debate, in large parts because
of the observational challenges involved. Velocities for many stars in
the highly crowded cluster centres must be measured to constrain the
presence of an IMBH. I will summarize our previous efforts to search for
these objects and also highlight the role MUSE will play in this field
in the future. This new spectrograph allows us to obtain samples of up
to 10000 stars per cluster in less than an hour of telescope time.
Thanks to the unprecedented sample sizes, it also enables us to pursue a
range of other science cases, ranging from the distribution of binary
periods in the clusters to the study of stellar populations.