Chemistry in the cold, warm, and hot interstellar medium Available to Purchase

In this paper, we discuss the chemistry that occurs in the cold dense interstellar medium and as temperatures rise above standard interstellar cloud values due to star formation or other energetic processes. During the warm up to the hot core stage (100–300 K), a radical photochemistry on grain surfaces leads to the formation of complex organic molecules (COMs), which then desorb into the gas, where they are detected. At still higher temperatures, it is necessary to consider a large number of additional gas-phase reactions that become important. We emphasize a new high-temperature gas-phase network that is capable of being used in simulations of the chemistry that occurs at temperatures up to 800–1000 K. Examples are given. It is also possible that a very high temperature surface chemistry, in which species other than atomic hydrogen stick to grains via strong chemisorption forces, occurs.