Stellar Populations of UV-Selected Active Galactic Nuclei Host Galaxies
  at z ~ 2 - 3
  We use stellar population synthesis modeling to analyze the host galaxy
properties of a sample of 33 UV-selected, narrow-lined active galactic nuclei
(AGNs) at z ~ 2 - 3. In order to quantify the contribution of AGN emission to
host galaxy broadband spectral energy distributions (SEDs), we use the
subsample of 11 AGNs with photometric coverage spanning from rest-frame UV
through near-IR wavelengths. Modeling the SEDs of these objects with a linear
combination of stellar population and AGN templates, we infer the effect of the
AGN on derived stellar population parameters. We also estimate the typical bias
in derived stellar populations for AGNs lacking rest-frame near-IR wavelength
coverage, and develop a method for inferring the true host galaxy properties.
We compare AGN host galaxy properties to those of a sample of UV-selected,
star-forming non-AGNs in the same redshift range, including a subsample
carefully matched in stellar mass. Although the AGNs have higher masses and
SFRs than the full non-active sample, their stellar population properties are
consistent with those of the mass-selected sample, suggesting that the presence
of an AGN is not connected with the cessation of star-formation activity in
star-forming galaxies at z ~ 2 - 3. We suggest that a correlation between M_BH
and galaxy stellar mass is already in place at this epoch. Assuming a roughly
constant Eddington ratio for AGNs at all stellar masses, we are unable to
detect the AGNs in low-mass galaxies because they are simply too faint.
