Early Science with the Large Millimeter Telescope: Exploring the Effect
  of AGN Activity on the Relationships Between Molecular Gas, Dust, and Star
  Formation
  The molecular gas, H$_2$, that fuels star formation in galaxies is difficult
to observe directly. As such, the ratio of $L_{\rm IR}$ to $L^\prime_{\rm CO}$
is an observational estimation of the star formation rate compared with the
amount of molecular gas available to form stars, which is related to the star
formation efficiency and the inverse of the gas consumption timescale. We test
what effect an IR luminous AGN has on the ratio $L_{\rm IR}/L^\prime_{\rm CO}$
in a sample of 24 intermediate redshift galaxies from the 5 mJy Unbiased
Spitzer Extragalactic Survey (5MUSES). We obtain new CO(1-0) observations with
the Redshift Search Receiver on the Large Millimeter Telescope. We diagnose the
presence and strength of an AGN using Spitzer IRS spectroscopy. We find that
removing the AGN contribution to $L_{\rm IR}^{\rm tot}$ results in a mean
$L_{\rm IR}^{\rm SF}/L^\prime_{\rm CO}$ for our entire sample consistent with
the mean $L_{\rm IR}/L^\prime_{\rm CO}$ derived for a large sample of star
forming galaxies from $z\sim0-3$. We also include in our comparison the
relative amount of polycyclic aromatic hydrocarbon emission for our sample and
a literature sample of local and high redshift Ultra Luminous Infrared Galaxies
and find a consistent trend between $L_{6.2}/L_{\rm IR}^{\rm SF}$ and $L_{\rm
IR}^{\rm SF}/L^\prime_{\rm CO}$, such that small dust grain emission decreases
with increasing $L_{\rm IR}^{\rm SF}/L^\prime_{\rm CO}$ for both local and high
redshift dusty galaxies.
