Astrochemical Kinetic Grid Models of Groups of Observed Molecular
  Abundances: Taurus Molecular Cloud 1 (TMC-1)
  The emission line spectra of cyanoacetylene and methanol reveal chemical and
physical heterogeneity on very small (< 0.1 pc) scales toward the peak in
cyanopolyyne emission in the Taurus Molecular Cloud, TMC-1 (CP). We generate
grids of homogeneous chemical models using a three-phase rate equation approach
to obtain all time-dependent abundances spanning the physical conditions
determined from molecular tracers of compact and extended regions of emission
along this line of sight. Each time-dependent abundance is characterized by one
of four features: a maximum/minimum, a monotonic increase/decrease, oscillatory
behavior, or inertness. We similarly classify the time-dependent agreement
between modeled and observed abundances by calculating both the
root-mean-square logarithm difference and root-mean-square deviation between
the modeled and observed abundances at every point in our grid models for three
groups of molecules: (i) a composite group of all species present in both the
observations and our chemical network G, (ii) the cyanopolyynes C = {HC$_3$N,
HC$_5$N, HC$_7$N, HC$_9$N}, and (iii) the oxygen-containing organic species
methanol and acetaldehyde S = {CH$_3$OH, CH$_3$CHO}. We discuss how the
Bayesian uncertainties in the observed abundances constrain solutions within
the grids of chemical models. The calculated best fit times at each grid point
for each group are tabulated to reveal the minimum solution space of the grid
models and the effects the Bayesian uncertainties have on the grid model
solutions. The results of this approach separate the effect different physical
conditions and model-free parameters have on reproducing accurately the
abundances of different groups of observed molecular species.
