After having learned about the atypical academic career of our researcher Romane le Gal, it is now time to dwell on the peculiarities of her work: astrochimist, what exactly it is ? Some might have in mind the somewhat crazy vision of a researcher locked in a laboratory full of strange science trinkets, spending whole nights writing equations at the corner of a telescope.Myth or reality ? Let’s shed some light on a job that will not leave you without surprises.
A computer, a telescope and the sky for playground
Clichés lovers of “Back to the future” may be disappointed because, as explained by Romane, “astrochemistry is above all a lot of computer modeling“. Astrochemistry differs from astrobiology (search for potential organisms or traces of life on exoplanets), in that it is the study of molecular elements in distant spaces. Thus, Romane attempts to numerically model and analyze data from telescopic observations. To analyze and understand these molecules is to study their light spectrum, their wavelength and their state of excitation.”It’s sort of radioastronomy” to use the words of Romane. Radio telescopes scan the sky for particular frequencies characteristic of the spectrum of certain molecules.
These molecules are then analyzed in different environments, to study the chemical properties. In particular, interstellar clouds, composed of gas and dust. There are several types of clouds: diffuse clouds, not very dense and mostly composed of light atoms such as hydrogen and helium. And the giant molecular clouds, denser, often composed of the remains of a Supernova. Due to their density, these clouds host heavier elements (carbon, iron …) and protect the billions of atoms that compose them from cosmic radiation. This protection then favors the creation of more complex molecules. After a while and with the effect of gravity, the gases and dust condense and form a rotating disk around a “proto-star” in the making. It is for this reason that we call them the “nurseries of stars” …
Understand the mysteries of the universe and our origins
All the work of Romane consists in the study of these complex molecules, and this within the Milky Way, but also in extragalactic environments. For example, she has studied the nebula “horse head” (a study that you can find in open access here).
Whether intra or extragalactic these molecules are located several light years from the earth. As a reminder, a light year is not a unit of time but of distance, and it is exactly 9,460,730 billion kilometers. The molecules observed are therefore at distances that quickly become … astronomical.
The light that emanates from it travels at a speed of 300 000 km / s, and therefore takes a while to reach us.So, when Romane observes through her telescope, she travels. She travels in a way through time and space … “and that’s the beauty and philosophy of my job” she said.
“My goal is to find complex molecules within these clouds, such as amino acids, components of the living, and trace their origins.The whole question is whether these molecules could become more complex in these clouds, before to be transported by stellar winds, asteroids or meteorites (in which case they could very well have developed on other exoplanets) … or, if they become really unique once in a favorable environment like the Earth. ”
We hope that through these words the work of Romane will be illustrated to its true value, and that you readers, will now look from a different eye the status of researcher, and the starry sky …