Astrochemistry & Astrobiology

Gas in the Universe is made up of ions and molecules, which are governed by complex astrochemical processes that operate on a huge range of physical scales throughout the Universe. On the smallest scales, the chemistry of exoplanet atmospheres gives us key insights into the physical conditions on distant worlds, whilst the chemistry of proto-planetary discs influences how these planets form. On intermediate scales, the chemistry of interstellar gas in galaxies determines how the gas cools and collapses to form molecular clouds, thereby regulating the birth of new stars in these stellar nurseries. Chemical processes also play a vital role on large scales, for example by governing how gas in the circum-galactic and inter-galactic medium cools and feeds galaxy formation.

The astrochemistry and astrobiology research at the E.A. Milne Centre explores chemical processes across this full range of physical scales. On the smallest scales, we develop advanced computational techniques to predict vibrational and electronic signatures of molecules adsorbed on dust grains. Understanding such spectroscopic signatures, we can detect molecular entities in various interstellar ices and explore a lesser-known part of astrophysics at the solid-gas interface. We also actively devise novel approaches for large-scale computation of spectral signatures of the many possible biomarkers on other planets and satellites. This field has implications for planetary formation, origin of carbon reservoirs, exoplanets and origins of life.

On larger scales, we implement complex astrochemical reaction networks into cosmological simulations of galaxy formation to understand the chemical evolution of interstellar gas. These advanced chemical models accurately capture how gas cools in these simulations, which allows us to explore how these processes affect the formation and evolution of galaxies. We also use this chemical modelling to create synthetic observations of the spectroscopic chemical signatures from the interstellar medium, which enables us to compare our simulation predictions directly to observational data.