Chemical sensitivity to the ratio of the cosmic-ray ionization rates of He and H<sub>2</sub>in dense clouds
Chemical sensitivity to the ratio of the cosmic-ray ionization rates of He and H<sub>2</sub>in dense clouds
Aims.To determine whether or not gas-phase chemical models with homogeneous and time-independent physical conditions explain the many observed molecular abundances in astrophysical sources, it is crucial to estimate the uncertainties in the calculated abundances and compare them with the observed abundances and their uncertainties. Non linear amplification of the error …