  We analyze a suite of $30$ high resolution zoom-in cosmological hydrodynamic
simulations of massive galaxies with stellar masses $M_{\ast} > 10^{10.9}
M_\odot$, with the goal of better understanding merger activity in AGN, AGN
activity in merging systems, SMBH growth during mergers, and the role of gas
content. Using the radiative transfer code \textsc{Powderday}, we generate
HST-WFC3 F160W mock observations of redshift $0.5 < z < 3$ central galaxies,
add noise properties similar to the CANDELS survey, and measure morphological
properties from the synthetic images using commonly adopted non-parametric
statistics. We compare the distributions of morphological properties measured
from the synthetic images with a sample of inactive galaxies and X-ray selected
AGN hosts from CANDELS. We study the connection between mergers and AGN
activity in the simulations, the synthetic images, and the observed CANDELS
sample. We find that, in both the simulations and CANDELS, even the most
luminous $(L_{\rm bol} > 10^{45}$ erg s$^{-1})$ AGN in our sample are no more
likely than inactive galaxies $(L_{\rm bol} < 10^{43}$ erg s$^{-1})$ to be
found in merging systems. We also find that AGN activity is not overall
enhanced by mergers, nor enhanced at any specific time in the $1$ Gyr preceding
and following a merger. Even gas rich major mergers (stellar mass ratio $>$1:4)
do not necessarily enhance AGN activity or significantly grow the central SMBH.
We conclude that in the simulated massive galaxies studied here, mergers are
not the primary drivers of AGN.
