Expanding the submillimeter wave spectroscopy and astronomical search
  for thioacetamide (CH3CSNH2) in the ISM
  Thioacetamide (CH3CSNH2) is the sulfur analog to acetamide (CH3CONH2) and it
is a viable candidate to search for in astronomical environments specifically
toward regions where other S-bearing molecules have been found and, if
possible, that also contain a detection of CH3CONH2. If detected, it would not
only continue to expand the view of molecular complexity in astronomical
environments, but also help to better elucidate the possible formation pathways
of these types of species in these environments. The rotational spectrum of
CH3CSNH2 was investigated up to 650 GHz. Using the newly refined spectrum of
CH3CSNH2, as well as additional spectroscopic data on the chemically related
species CH3CONH2, a variety of astronomical sources were searched including
data from the following large surveys: The PRIMOS conducted with the Green Bank
Telescope (GBT); Exploring molecular complexity with ALMA (EMoCA) conducted
with ALMA; and Astrochemical Surveys at IRAM (ASAI) conducted with the Institut
de Radioastronomie Millimetrique (IRAM) 30m Telescope. A total of 1428
transitions from the vt=0 state with maximum values J=47 and Ka=20 in the range
up to 330 GHz, and J=95 and Ka=20 in the range from 400 - 660 GHz were
assigned. We also assigned 321 transitions from the vt=1 state with the maximum
values J=35 and Ka=9 up to 330 GHz. The final fit is based on the
rho-axis-method (RAM) Hamiltonian model that includes 40 parameters. An
astronomical search for CH3CSNH2 was conducted based on all the new
spectroscopic data. No transitions of CH3CSNH2 were detected toward any of the
sources contained in our survey. Using the appropriate telescope and physical
parameters for each astronomical source, upper limits to the column densities
were found for CH3CSNH2 toward each source.
