Globular clusters hosting intermediate-mass black-holes: no
  mass-segregation based candidates
  Recently, both stellar mass-segregation and binary-fractions were uniformly
measured on relatively large samples of Galactic Globular Clusters (GCs).
Simulations show that both sizeable binary-star populations and
Intermediate-Mass Black Holes (IMBHs) quench mass-segregation in relaxed GCs.
Thus mass-segregation in GCs with a reliable binary-fraction measurement is a
valuable probe to constrain IMBHs. In this paper we combine mass-segregation
and binary-fraction measurements from the literature to build a sample of 33
GCs (with measured core-binary fractions), and a sample of 43 GCs (with a
binary fraction measurement in the area between the core radius and the
half-mass radius). Within both samples we try to identify IMBH-host candidates.
These should have relatively low mass-segregation, a low binary fraction (<
5%), and short (< 1 Gyr) relaxation time. Considering the core binary fraction
sample, no suitable candidates emerge. If the binary fraction between the core
and the half-mass radius is considered, two candidates are found, but this is
likely due to statistical fluctuations. We also consider a larger sample of 54
GCs where we obtained an estimate of the core binary fraction using a
predictive relation based on metallicity and integrated absolute magnitude.
Also in this case no suitable candidates are found. Finally, we consider the GC
core- to half-mass radius ratio, that is expected to be larger for GCs
containing either an IMBH or binaries. We find that GCs with large core- to
half-mass radius ratios are less mass-segregated (and show a larger binary
fraction), confirming the theoretical expectation that the energy sources
responsible for the large core are also quenching mass-segregation
