Radiative Transfer of HCN: Interpreting observations of hyperfine anomalies

  title={Radiative Transfer of HCN: Interpreting observations of hyperfine anomalies},
  author={A. M. Mullins and Robert M. Loughnane and Matt Redman and B. Wiles and Nelly Guegan and Justin Barrett and Eric R. Keto},
  journal={Monthly Notices of the Royal Astronomical Society},
Molecules with hyperfine splitting of their rotational line spectra are useful probes of optical depth, via the relative line strengths of their hyperfine components.The hyperfine splitting is particularly advantageous in interpreting the physical conditions of the emitting gas because with a second rotational transition, both gas density and temperature can be derived. For HCN however, the relative strengths of the hyperfine lines are anomalous. They appear in ratios which can vary… 

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