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| According to Anton Vasyunin, scientists have obtained important information about the composition of interstellar ice. Photo Credit: UrFU press service |
A team of scientists from the Laboratory of Astrochemical Research at UrFU has for the first time determined the amount of methane in gas and dust in the young star-forming region IRAS 23385+6053. The results of the study are important for understanding the mechanisms of formation of the prebiotically important methane molecule in space. The scientists published a description of the study in The Astrophysical Journal Letters.
"Observations in the infrared provide a unique opportunity to simultaneously study interstellar gas and interstellar ice. This is not possible in other wavelength ranges. Thanks to the launch of the new James Webb Space Telescope, the quality of the infrared spectra of star-forming regions has been significantly improved and has made it possible to study the composition of interstellar ice and interstellar gas simultaneously with high precision. To analyze the spectra of the protostar IRAS 23385+6053 obtained from the telescope, we used the ISEAge facility of the Ural Federal University, which allows us to grow and study space ice analogs under conditions of ultra-high vacuum and ultra-low temperatures," said the author of the article, Ruslan Nakibov, a research laboratory assistant at the Laboratory of Astrochemical Research of the Ural Federal University.
The uniqueness of this work is that for the first time interstellar dust and interstellar gas were analyzed simultaneously. The scientists found out how much methane is on the dust in the form of ice and how much is in the interstellar gas. It was found that methane can be found on the surface of a dust particle surrounded by water and carbon dioxide, with about 15% of all methane in the object being in the gas. The findings help determine the mechanisms of methane formation in interstellar clouds. As the researchers explain, depending on how methane is formed, its ratio in gas and in ice differs.
"We have obtained important information about the composition of interstellar ice, which will then probably form complex organic molecules. Some of it will probably turn into oceans on future planets," adds Anton Vasyunin, Head of the Astrochemistry Laboratory at UrFU.
The observed object IRAS 23385+6053 has long been of interest to astronomers. It is a young star-forming region with a large mass, a complex structure including six dense nuclei, two young stellar objects located close to each other and three high-speed outflows. It consists of relatively cold gas and dust (nearly 50 Kelvin or -223 ℃) and warm gas (nearly 400 Kelvin or +127 ℃).
"Whether the properties we found are typical of all such protostars or not, we don't know for sure yet. The region of IRAS 23385+6053 in terms of the shape of the methane spectrum is slightly different in the small sample available so far that we have compared with. Whether it is a unique object or not, we cannot yet say for sure either. To establish this, we need to collect a large amount of data, new observations of protostars, which we plan to obtain using the JWST, and in the future - with the help of the latest Russian instruments," concludes Anton Vasyunin.
Reference Material:
Methane (CH4) is one of the most abundant molecules in the cosmos. It has been found in both solid and gaseous states in many objects of astrochemical significance: molecular clouds, protostars, comets, planetary atmospheres, exoplanets, and satellites. Methane also has astrobiological significance for planetary research: methane is arguably a biosignature, in other words, any manifestation of the effects of life scientifically proving the existence of life in the past or present.
In gas and dust clouds, methane is either in the gaseous or icy state. Gaseous methane is found in interstellar gas, while icy methane is found in the ice crusts (mantles) of microscopic interstellar dust particles. The mantles are composed of different molecules (water, carbon monoxide and dioxide, ammonia, methane, etc.), and it is believed that chemical reactions take place in them, which, for example, lead to the formation of complex organic molecules that later develop into organic matter.
Funding: The work was supported by the Russian Science Foundation (project No. 23-13-00315).
Published in journal: The Astrophysical Journal Letters
Title: Solid and Gaseous Methane in IRAS 23385+6053 as Seen with Open JWST Data
Authors: Ruslan Nakibov, Varvara Karteyeva, Igor Petrashkevich, Maksim Ozhiganov, Mikhail Medvedev, and Anton Vasyunin
Source/Credit: Ural Federal University | Anna Marinovich
Reference Number: sn012825_01