抄録
We first describe physical and chemical properties of interstellar medium in each of six different phases: coronal gas, intercloud medium, H II region, diffuse cloud, dark cloud, and molecular cloud. Theoretical studies on the interstellar chemistry are summarized briefly. A detailed model for the gas-phase chemistry in dense insterstellar clouds is presented. We calculate the abundances of the various molecules for pseudo-time-dependent model, in which the physical conditions are assumed to be constant. Our result indicates that the gas-phase reactions can produce large abundances of complex molecules at time well before steady state is reached. We also study the gas-phase chemistry as a function of gas density and temperature.
The preliminary results on the chemical evolution of the contracting interstellar clouds are represented. Models and rate coefficients of the gas-phase chemistry, the effects of dust grains, and the implications of our theoretical results are also discussed.
