Author(s): , , ,
Institution(s): 1. Lorand Eotvos University, 2. National Astronomical Observatories of China, Chinese Academy of Sciences
We present a set of time dependent chemical evolution models (based on the UMIST astrochemistry 2012 code) for the wide range of initial physical cloud parameters (T = 10K - 20K, n(H2) = 1e3 - 5e4 cm-3, AV = 1 - 10 and with the few values of scaled interstellar ultraviolet radiation field). Our computation model include the full UMIST gas-phase reaction network 6173 which contain the whole set of 467 species. We compare our detail chemical model results with the relative abundances of the: CO, CH, OH, HCO+, HCN, HNC, NH3, N2H+ and H2CO molecules. For a selected dark cloud TMC-1 (Taurus Molecular Cloud-1) we find a significant time dependent changes of the chemical ratios: OH/CH, NH3/SO and HCN/N2H+ together with the almost time independent (i.e. constant) OH/CO values.