Star Clusters in Pseudo-Bulges of Spiral Galaxies
  We present a study of the properties of the star-cluster systems around
pseudo-bulges of late-type spiral galaxies using a sample of 11 galaxies with
distances from 17 to 37 Mpc. Star clusters are identified from multiband HST
ACS and WFPC2 imaging data by combining detections in 3 bands (F435W and F814W
with ACS and F606W with WFPC2). The photometric data are then compared to
population synthesis models to infer the masses and ages of the star clusters.
Photometric errors and completeness are estimated by means of artificial source
Monte Carlo simulations. Dust extinction is estimated by considering F160W
NICMOS observations of the central regions of the galaxies, augmenting our
wavelength coverage. In all galaxies we identify star clusters with a wide
range of ages, from young (age < 8 Myr) blue clusters, with typical mass of
10^3 Msun to older (age > 100-250 Myr), more massive, red clusters. Some of the
latter might likely evolve into objects similar to the Milky Way's globular
clusters. We compute the specific frequencies for the older clusters with
respect to the galaxy and bulge luminosities. Specific frequencies relative to
the galaxy light appear consistent with the globular cluster specific
frequencies of early-type spirals. We compare the specific frequencies relative
to the bulge light with the globular cluster specific frequencies of dwarf
galaxies, which have a surface-brightness profile that is similar to that of
the pseudo-bulges in our sample. The specific frequencies we derive for our
sample galaxies are higher than those of the dwarf galaxies, supporting an
evolutionary scenario in which some of the dwarf galaxies might be the remnants
of harassed late-type spiral galaxies which hosted a pseudo-bulge.
