The Milky Way is not low in fat: a new study reveals facts about fat in the space

Astronomers from UNSW Sydney and the Ege University in Turkey used a laboratory to make materials with the same properties as interstellar dust and used their results to estimate the amount of "space fat" found in the Milky Way . Their results appear in an article in Monthly Notices of the Royal Astronomical Society.

Organic matter of different types contains carbon, an element considered essential to life. However, there is real uncertainty about its abundance, and only half of the expected carbon is between the stars in its pure form. The rest is chemically bound in two main forms: greasy (aliphatic) and mothproof (aromatic).

The UNSW / Ege team mimicked the process by which organic molecules are synthesized in carbon starflows, deploying a carbon-containing plasma in a low-temperature vacuum. The material was collected and badyzed by a combination of techniques. Using magnetic resonance and spectroscopy (separating light in its constituent wavelengths), they were able to determine to what extent the material absorbed light with a certain infrared wavelength, a marker for carbon. aliphatic.

"The combination of our lab results with observations from astronomical observatories allows us to measure the amount of aliphatic carbon between us and the stars," says Professor Tim Schmidt of the Center for Excellence in Exciton Science. the Australian Research Council at UNSW.

The researchers discovered that there are about 100 fatty carbon atoms for every one million atoms of hydrogen, accounting for between one quarter and one half of the available carbon. In the Milky Way, this represents about 10 trillion trillion tons of fat, or enough for 40 trillion trillion packets of butter.

Schmidt is quick to dispel the comparison with something edible: "This space fat is not the kind of thing you'd like to spread on a slice of toast! It's dirty, probably toxic and only forms in the environment of interstellar space (and our laboratory) .It is also intriguing that organic matter of this kind – material that incorporates it into planetary systems – is so abundant. "

The team now wants to determine the abundance of carbon resembling mothballs, which will involve even more difficult work in the lab. By firmly establishing the amount of each type of carbon in the dust, they will know exactly how much of this element is available to create life.

The new work appears in "Aliphatic hydrocarbon content of interstellar dust", B. Günay, TW Schmidt, MG Burton, M. Afşar, O. Krechkivska, K. Nauta, SH Kable and A. Rawal, Monthly Notices of the Royal Astronomical Society, Oxford University Press, in press.