The UMIST database for astrochemistry 2022

Vol. 682
12. Atomic, molecular, and nuclear data

The UMIST database for astrochemistry 2022

Detailed astrochemical models are necessary for interpreting the observations of interstellar and circumstellar molecules. They depend on the values of the rate coefficients of individual chemical reactions, and these need to be continuously updated to reflect advances in experimental and theoretical estimates. In this volume, Tom Millar and collaborators present the sixth release of the UMIST Database for Astrochemistry, one of most widely used databases of gas-phase chemical reactions. Compared to the previous release from ten years ago, the new update increases the number of reactions by over 40% and the number of species by over 55%. Making use of it, Millar et al. investigate the gas-phase chemistries appropriate to the dark cloud TMC-1 and the circumstellar envelope IRC+10216, and identify the successes and failures of gas-phase-only models.