Near the center of the Milky Way, in a vast cloud in the space between the stars, a team of astronomers has identified an organic molecule never before detected in the interstellar medium. It’s called propargylamine, and it could play a key role in the formation of amino acids vital for the emergence of life.
Laboratory experiments at the Center for Astrochemical Studies (CAS) of the Max Planck Institute for Extraterrestrial Physics (MPE) in Munich, as well as astronomical observations from the Italian National Institute for Astrophysics (INAF), have led to the identification of this new molecule. in the molecular cloud known as G + 0.693-0.027, near the galactic center.
Propargylamine has the chemical formula HCCCHNH and is an unstable compound . It is very difficult to isolate under normal conditions from Earth’s atmosphere, but it thrives at low densities and temperatures typical of the interstellar medium.
” The particularity of this chemical species lies in its carbon-nitrogen double bond, which gives it high reactivity. With this double bond it becomes a fundamental component of the chemical chains that come from the simplest and most abundant molecules in space that they contain carbon and nitrogen – for example formaldehyde (H2CO) and ammonia (NH3), respectively – to the most complex amino acids, the fundamental building blocks of terrestrial biology, “explains astrochemist Luca Bizzocchi of the Max Planck Institute for Extraterrestrial Physics in Germany. .
The area where this organic molecule was discovered is a cloud system rich in molecular gas. It is called the Central Molecular Zone, an area of great interest to astrochemists, as it represents a large deposit of complex astrophysical organic molecules, such as ethyl formate, isopropyl cyanide, and propylene oxide. They are known as prebiotic molecules, since they play a key role in the prebiotic processes that create the basic components of life, such as amino acids, RNA and DNA, so the discovery of propargylamine represents a promising candidate for a new interstellar detection.
Studying Propargylamine in the Laboratory
The aim of the study was to conduct a comprehensive laboratory investigation of the rotation spectrum of propargylamine in its ground vibratory state to obtain a highly accurate set of resting frequencies and search for it in space. Measurements were made using a source modulation millimeter wave spectrometer, equipped with a pyrolysis system for the production of unstable species.
” As a molecule rotates in the interstellar medium, it emits photons at very precise frequencies ,” says Bizzocchi. “This information, when combined with data from radio telescopes, allows us to know if a molecule is present in molecular clouds, the sites of star and planet formation.”
The experts recorded the rotational spectra of two isomers, or atomic configurations, of propargylamine in the laboratory, adding around 1,000 rotational transitions , allowing to create an incredibly precise spectral profile of propargylamine, which explains the distortion that the molecule undergoes in space.
Then, they compared these results with spectral observations made with the 30-meter telescope in Sierra Nevada (Spain), focusing on the G + 0.693-0.027 cloud. And just as they expected: “Our molecule was there,” explained astrophysicist Víctor M. Rivilla, from the National Institute of Astrophysics in Italy.
What other secrets does our cosmos hide? Little by little we continue to discover them.
Referencia: Propargylimine in the laboratory and in space: millimetre-wave spectroscopy and first detection in the ISM, arXiv:2006.08401 [astro-ph.GA] arxiv.org/abs/2006.08401
