A Large Population of Obscured AGN in Disguise as Low Luminosity AGN in
  Chandra Deep Field South
  Population synthesis models of actively accreting super-massive black holes
(or active galactic nuclei -- AGN) predict a large fraction that must grow
behind dense, obscuring screens of gas and dust. Deep X-ray surveys are thought
to have provided the most complete and unbiased samples of AGN, but there is
strong observational evidence that a portion of the population of obscured AGN
is being missed. In this paper we use a sample of AGN derived from the deepest
X-ray survey to date, the Chandra 7Ms GOODS-South Survey, to investigate the
nature of low flux X-ray sources. We make full use of the extensive
multi-wavelength coverage of the GOODS-South field, and cross-match our objects
with wavelengths from the Radio to the IR. We find the low X-ray flux AGN in
our sample have X-ray luminosities that indicate low-luminosity AGN
classification, while their radio, infrared and optical counterparts indicate
moderate to powerful AGN classification. We find the predicted column densities
is on average an order of magnitude higher than the calculated column densities
via X-ray detections for X-ray faint sources. We interpret our results as
evidence of obscured AGN disguising as low-luminosity AGN via their X-ray
luminosities. When we compare the estimation of the obscured AGN space density
with and without these objects, we find a difference of 40% in the lowest X-ray
luminosity regime probed by our sample.
