  In recent years, increasing evidence for chemical complexity and multiple
stellar populations in massive globular clusters (GCs) has emerged, including
extreme horizontal branches (EHBs) and UV excess. Our goal is to improve our
understanding of UV excess in the regime of both massive GCs and ultra-compact
dwarf galaxies (UCDs). To this end, we use deep archival GALEX data of the
central Fornax cluster to measure NUV and FUV magnitudes of UCDs and massive
GCs. We obtain NUV photometry for a sample of 35 compact objects with
-13.5<M_V<-10 mag. Of those, 21 objects also have FUV photometry. Roughly half
of the sources fall into the UCD luminosity regime (M_V <=-11 mag). We find
that seven out of 17 massive Fornax GCs exhibit a NUV excess with respect to
expectations from stellar population models, even for models with enhanced
Helium abundance. This suggests that not only He-enrichment has contributed to
forming the EHB population of these GCs. The GCs extend to stronger UV excess
than GCs in M31 and massive GCs in M87, at the 97% confidence level. Most of
the UCDs with FUV photometry also show evidence for UV excess, but their UV
colours can be matched by isochrones with enhanced Helium abundances and old
ages 12-14 Gyrs. We find that Fornax compact objects with X-ray emission
detected from Chandra images are almost disjunct in colour from compact objects
with GALEX UV detection, with only one X-ray source among the 35 compact
objects. However, since this source is one of the three most UV bright GCs, we
cannot exclude that the physical processes causing X-ray emission also
contribute to some of the observed UV excess.
