Specific Frequencies and Luminosity Profiles of Cluster Galaxies and
  Intracluster Light in Abell 1689
  We present magnitudes and profile fits for 180 galaxies in the central field
of the massive lensing cluster Abell 1689 using very deep imaging with the
ACS/HST in the F814W bandpass. Previous work revealed an exceptionally large
number of globular clusters (GCs) in A1689 and mapped their number density
distribution. We decompose this number density map into GCs associated with
individual cluster galaxies and ICGCs (intracluster globular clusters)
associated with the intracluster light (ICL). In all, we measure GC specific
frequencies $S_N$ for 33 cluster members and the ICL. The relation between
$S_N$ and galaxy magnitude is consistent with the trend observed in Virgo,
although some intermediate luminosity galaxies scatter to $S_N>10$. We estimate
the ICL makes up 11% of the starlight in this field, whereas the ICGCs account
for $\sim\,$35% of the GCs, both consistent with predictions from simulations.
Galaxies with higher $S_N$ values tend to be rounder, and there is a marginally
significant trend of decreasing $S_N$ with increasing specific angular momenta
$\lambda_R$. We also reevaluate the GC population in the A2744 Frontier Field,
for which fewer than one-tenth as many GCs have been detected because of its
larger distance. Finally, our core-S\'ersic fit to the light profile of the
A1689 BCG implies a break radius of 3.8kpc, among the largest known; we discuss
implications of the sizable core and extensive GC population for the
supermassive black hole in light of scaling relations.
