The Global Mass Functions of 35 Galactic globular clusters: II. Clues on
  the Initial Mass Function and Black Hole Retention Fraction
  In this paper we compare the mass function slopes of Galactic globular
clusters recently determined by Sollima & Baumgardt (2017) with a set of
dedicated N-body simulations of star clusters containing between 65,000 to
200,000 stars. We study clusters starting with a range of initial mass
functions (IMFs), black hole retention fractions and orbital parameters in the
parent galaxy. We find that the present-day mass functions of globular clusters
agree well with those expected for star clusters starting with Kroupa or
Chabrier IMFs, and are incompatible with clusters starting with single
power-law mass functions for the low-mass stars. The amount of mass segregation
seen in the globular clusters studied by Sollima & Baumgardt (2017) can be
fully explained by two-body relaxation driven mass segregation from initially
unsegregated star clusters. Based on the present-day global mass functions, we
expect that a typical globular cluster in our sample has lost about 75% of its
mass since formation, while the most evolved clusters have already lost more
than 90% of their initial mass and should dissolve within the next 1 to 2 Gyr.
Most clusters studied by Sollima & Baumgardt also show a large difference
between their central and global MF slopes, implying that the majority of
Galactic globular clusters is either near or already past core collapse. The
strong mass segregation seen in most clusters also implies that only a small
fraction of all black holes formed in globular clusters still reside in them.
