Jose Angel Martín-Gago
ESINA group. ICMM-CSIC, Spain
Nanosruf lab. FZU, Czech Republic
Nanoscience to understand dust and organic molecular formation in the cosmos
Evolved stars are a factory of chemical complexity, gas and dust, which contribute to the building blocks of planets and life. However, the dust and gas formation processes remain poorly understood. Different laboratory techniques are used to produce analogs of cosmic dust being based the majority of them on uncontrolled combustion or plasma decomposition of molecular precursors in conditions far removed from those in star photospheres.
We have designed and built an unprecedented ultra-high vacuum machine combining gas aggregation sources with in-situ advanced surface science characterization techniques (as STM, XPS or IRAS) and mass spectroscopy [1]. We show that astrochemical problems can be successfully addressed and understood using surface science methodologies. This combination opens the door to the investigation and modelling of processes related to dust particles and its interaction with the gas in different regions of the universe.
Different model systems will be presented. In the first analogues of cosmic dust are analysed to conclude that evolved stars do not form aromatics or fullerenes but aliphatic material made up by bottom-up coalescence[2]. In the second example we propose a new route for the formation of polycyclic aromatic hydrocarbons produced by etching of graphene on the SiC grains in a top-down process[3].
References
[1] L. Martinez, Sci Rep. 8 (2018) 7250. / G Santoro, Review of Scientific Instruments 91 (2020), 124101
[2] L. Martinez, Nature Astronomy, 4 (2020), 97-105 /M Accolla, The Astrophysical Journal 906 (2021),44
[3] Merino P., et al. Nature Communications 5, (2014), 3054