Unlocking the chemistry of the heavens
How are the building blocks of life formed?
- Harold Linnartz
- NWO Vici 2009
- More information about the Sackler Laboratory for Astrophysics
Exotic chemical reactions take place between and around stars. In spite of the low temperatures, strong radiation fields and low densities, complex molecules are still formed. Linnartz will be imitating this process in a lab environment to explain the presence of molecules observed in space.
The conditions in space are extreme and not in favour of an efficient chemistry: temperatures are low, radiation fields are intense and particle densities are exceedingly small. Nevertheless, more than 150 different molecular species have been identified in star-forming regions. These comprise both small and complex species as well as stable and transient molecules and are the result of a largely unknown chemical evolution.
Many other astrophysically relevant species still lack unambiguous identifications. Today, astrochemists explain the chemical complexity in space as the cumulative outcome of gas, grain and gas-grain interactions. Gas phase models explain the observed abundances of exotic molecules such as the linear carbon chain radical HCCCCCCCCCCCN, but such models fail to explain the presence of stable species, such as acetonitrile, a precursor molecule for the simplest amino acid glycine.
Evidence has been found that these species form on icy dust grains that act as catalytic sites for molecule formation. Thermal and ultraviolet processing as well as atom bombardment of inter- and circumstellar ices trigger a fascinating but largely unexplored solid state chemistry.
My group works at the fore-front to identify molecules of astrophysical interest and to characterize astrochemical solid state formation routes. In the last years we have investigated fundamental properties of inter- and circumstellar ice analogues; infrared and optical spectra, thermal and photodesorption rates, reaction schemes and rates; and molecular transients of astrophysical interest and the goal of this proposal is to lift our findings into the next phase -toward molecular complexity- searching for the keys to unlock the chemistry of the heavens.
Support is requested to expand and to further exploit existing laboratory experiments with the aim to study chemical processes in inter- and circumstellar ice analogues and spectroscopic features of radical species in cold plasma. The laboratory results are used to guide and to interpret astronomical observations and the main return to the astronomical community is the ability to use data from a variety of observational facilities far more effectively than possible otherwise.