First Acetic Acid Survey with CARMA in Hot Molecular Cores
  Acetic acid (CH$_3$COOH) has been detected mainly in hot molecular cores
where the distribution between oxygen (O) and nitrogen (N) containing molecular
species is co-spatial within the telescope beam. Previous work has presumed
that similar cores with co-spatial O and N species may be an indicator for
detecting acetic acid. However, does this presumption hold as higher spatial
resolution observations become available of large O and N-containing molecules?
As the number of detected acetic acid sources is still low, more observations
are needed to support this postulate. In this paper, we report the first acetic
acid survey conducted with the Combined Array for Research in Millimeter-wave
Astronomy (CARMA) at 3 mm wavelengths towards G19.61-0.23, G29.96-0.02 and IRAS
16293-2422. We have successfully detected CH$_3$COOH via two transitions toward
G19.61-0.23 and tentatively confirmed the detection toward IRAS 16293-2422 A.
The determined column density of CH$_3$COOH is 2.0(1.0)$\times 10^{16}$
cm$^{-2}$ and the abundance ratio of CH$_3$COOH to methyl formate (HCOOCH$_3$)
is 2.2(0.1)$\times 10^{-1}$ toward G19.61-0.23. Toward IRAS 16293 A, the
determined column density of CH$_3$COOH is $\sim$ 1.6 $\times 10^{15}$
cm$^{-2}$ and the abundance ratio of CH$_3$COOH to methyl formate (HCOOCH$_3$)
is $\sim$ 1.0 $\times 10^{-1}$ both of which are consistent with abundance
ratios determined toward other hot cores. Finally, we model all known line
emission in our passband to determine physical conditions in the regions and
introduce a new metric to better reveal weak spectral features that are blended
with stronger lines or that may be near the 1-2$\sigma$ detection limit.
