Massive Star Cluster Formation and Destruction in Luminous Infrared
  Galaxies in GOALS II: An ACS/WFC3 Survey of Nearby LIRGs
  We present the results of a Hubble Space Telescope WFC3 near-UV and ACS/WFC
optical study into the star cluster populations of 10 luminous and
ultra-luminous infrared galaxies (U/LIRGs) in the Great Observatories All-Sky
LIRG Survey (GOALS). Through integrated broadband photometry we have derived
ages, masses, and extinctions for a total of 1027 star clusters in galaxies
with $d_{L} <$ 110 Mpc in order to avoid issues related to cluster blending.
The measured cluster age distribution slope of $dN/d\tau \propto \tau^{-0.5 +/-
0.2}$ is steeper than what has been observed in lower-luminosity star-forming
galaxies. Further, differences in the slope of the observed cluster age
distribution between inner- ($dN/d\tau \propto \tau^{-1.07 +/- 0.12}$) and
outer-disk ($dN/d\tau \propto \tau^{-0.37 +/- 0.09}$) star clusters provides
evidence of mass-dependent cluster destruction in the central regions of LIRGs
driven primarily by the combined effect of strong tidal shocks and encounters
with massive GMCs. Excluding the nuclear ring surrounding the Seyfert 1 nucleus
in NGC 7469, the derived cluster mass function (CMF: $dN/dM \propto
M^{\alpha}$) has marginal evidence for a truncation in the power-law (PL) at
$M_{t} \sim 2$x$10^{6} M_{\odot}$ for our three most cluster-rich galaxies,
which are all classified as early-stage mergers. Finally, we find evidence of a
flattening of the CMF slope of $dN/dM \propto M^{-1.42 \pm 0.1}$ for clusters
in late-stage mergers relative to early-stage ($\alpha = -1.65 \pm 0.02$),
which we attribute to an increase in the formation of massive clusters over the
course of the interaction.
