The radiation from stars and active galactic nuclei (AGNs) creates photodissociation regions
(PDRs) and X-ray-dominated regions (XDRs), where the chemistry or heating is dominated …

Molecular hydrogen is the most abundant molecule in the universe. It is the first one to form
and survive photo-dissociation in tenuous environments. Its formation involves catalytic …

This is a summary of the 2013 release of the plasma simulation code Cloudy. Cloudy
models the ionization, chemical, and thermal state of material that may be exposed to an …

We present the fifth release of the UMIST Database for Astrochemistry (UDfA). The new
reaction network contains 6173 gas-phase reactions, involving 467 species, 47 of which are …

Chemical models used to study the chemical composition of the gas and the ices in the
interstellar medium are based on a network of chemical reactions and associated rate …

Of the over 150 different molecular species detected in the interstellar and circumstellar
media, approximately 50 contain 6 or more atoms. These molecules, labeled complex by …

Until a decade ago, the only anion observed to play a prominent role in astrophysics was H–
. The bound–free transitions in H–dominate the visible opacity in stars with photospheric …

We present an extended version of the two-phase gas–grain code nautilus to the three-
phase modelling of gas and grain chemistry of cold cores. In this model, both the mantle and …

The cross-disciplinary field of astrochemistry exists to understand the formation, destruction,
and survival of molecules in astrophysical environments. Molecules in space are …

Cold dark clouds are nearby members of the densest and coldest phase in the Galactic
interstellar medium, and represent the most accessible sites where stars like our Sun are …