MIRAGE · Measuring Interstellar Reactions of Aromatics by Gas-phase Experiments
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2019-05-01 → 2021-04-30
- EU contribution
- €196,708
- Participants
- 1
- Scheme
- MSCA-IF-EF-ST
Lines connect the coordinator with its partners.
Results in brief
Measuring Interstellar Reactions of Aromatics by Gas-phase Experiments
Astrochemistry is a thriving research field that links together the seemingly disparate disciplines of chemistry and astronomy. Terrestrial chemistry is dominated by aromatic molecules (especially stable rings of carbon and hydrogen), which frequently serve as the building blocks of polymers and many biological compounds. Despite this, at the beginning of this MSCA in 2019, only one aromatic molecule, benzonitrile, had been detected in space using radio astronomy. Benzonitrile provides a key link to benzene, which may be a low-temperature precursor to polycyclic aromatic hydrocarbons (PAHs); molecules that are expected to be lurking in interstellar space but have eluded detected. The presence of aromatic molecules at very cold temperatures (around -263 °C) in interstellar space is difficult to explain. The MSCA EU-funded project MIRAGE (Measuring Interstellar Reactions of Aromatics by Gas-phase Experiments) aimed to measure chemical reactions of aromatic molecules, such as benzene, down to the low temperatures found in interstellar space. To do this, we combined the expertise in measuring low-temperature reactions in Rennes with a new technique (one of only a few in development worldwide) that uses microwave spectroscopy, the same kind of detection technique used in radio telescopes. The first objective of the action involved building and optimizing this new technique for the measurement of reaction products down to temperatures as low as those in interstellar space. This work is ongoing but has already resulted in a publication, with three more in preparation. The second objective was to use the world-class facilities already available in Rennes to measure how fast reactions between benzene and radicals proceed at low temperature and which products they form. This work resulted in three publications in both astronomy and chemistry journals. To best exploit the laboratory data collected in this MSCA, the fellow was trained by leaders in radio astronomy and astrochemical modelling, greatly expanding her skillset and promoting cross-disciplinary knowledge exchange. This training allowed her to aid in the search for other aromatic molecules in cold interstellar space, leading to the first detection of individual PAH molecules.
Data: CORDIS, © European Union
Project objective
The recent discovery of benzonitrile in a nearby cold molecular cloud (Taurus) marks the first detection of an aromatic species in the interstellar medium by radio astronomy. Benzonitrile provides a key link to benzene, which may be a low-temperature precursor to more complex polycyclic aromatic hydrocarbons (PAHs). Understanding the origin of PAHs will help answer fundamental questions about their role in forming interstellar dust as well as potentially prebiotic molecules—material that may be incorporated into new planetary systems. Computational models are used to pinpoint individual chemical pathways by inputting kinetic rates of various formation and destruction reactions and aiming to reproduce the molecular abundances determined by radio astronomy. Many of these rates have not been measured in the laboratory, especially at low temperature. The MIRAGE project aims to measure reaction kinetics of functionalized benzenes at temperatures relevant to the cold interstellar medium and use these measurements to understand radio observations of aromatics in Taurus molecular cloud. To do this, we will use a new technique in development at the Université de Rennes 1 that combines chirped-pulse (sub)mm-wave (CPMW) rotational spectroscopy with uniform supersonic flows generated by the CRESU technique. This apparatus (one of only a few in development worldwide) will be used to measure kinetics for reactions of benzene. These data are critical to accurately explain the observed abundance of benzonitrile, as well as predicting the abundances of other aromatic species currently targeted for detection.
Original text from CORDIS.
Participants
- UNIVERSITE DE RENNES I · RENNES CEDEXCoordinatorFrance
Links
Data: CORDIS, © European Union