Towards a census of super-compact massive galaxies in the Kilo Degree
  Survey
  The abundance of compact, massive, early-type galaxies (ETGs) provides
important constraints to galaxy formation scenarios. Thanks to the area
covered, depth, excellent spatial resolution and seeing, the ESO Public optical
Kilo Degree Survey (KiDS), carried out with the VLT Survey Telescope (VST),
offers a unique opportunity to conduct a complete census of the most compact
galaxies in the Universe. This paper presents a first census of such systems
from the first 156 square degrees of KiDS. Our analysis relies on g-, r-, and
i-band effective radii ($R_{\rm e}$), derived by fitting galaxy images with
PSF-convolved S\'ersic models, high-quality photometric redshifts, $z_{\rm
phot}$, estimated from machine learning techniques, and stellar masses, $M_{\rm
\star}$, calculated from KiDS aperture photometry. After massiveness ($M_{\rm
\star} > 8 \times 10^{10}\, \rm M_{\odot}$) and compactness ($R_{\rm e} < 1.5
\, \rm kpc$ in g-, r- and i-bands) criteria are applied, a visual inspection of
the candidates plus near-infrared photometry from VIKING-DR1 are used to refine
our sample. The final catalog, to be spectroscopically confirmed, consists of
92 systems in the redshift range $z \sim 0.2-0.7$. This sample, which we expect
to increase by a factor of ten over the total survey area, represents the first
attempt to select massive super-compact ETGs (MSCGs) in KiDS. We investigate
the impact of redshift systematics in the selection, finding that this seems to
be a major source of contamination in our sample. A preliminary analysis shows
that MSCGs exhibit negative internal colour gradients, consistent with a
passive evolution of these systems. We find that the number density of MSCGs is
only mildly consistent with predictions from simulations at $z>0.2$, while no
such system is found at $z < 0.2$.
