Webb made the first detection of an important carbon molecule
(Nanowerk News) An international team of scientists has used NASA’s James Webb Space Telescope to detect a new carbon compound in space for the first time. Known as the methyl cation (pronounced cat-eye-on) (CH3+), this molecule is important because it helps the formation of more complex carbon-based molecules. Methyl cations were detected in young star systems, with a protoplanetary disk, known as d203-506, which is located about 1,350 light-years away in the Orion Nebula.
These findings, which come from the PDRs4ALL Early Release Science program, have been published in the journal Natural (“Formation of Methyl Cations by Photochemistry in the Protoplanetary Disk”).
Carbon compounds form the basis of all known life, and are therefore of great interest to scientists working to understand how life developed on Earth, and how it could potentially develop elsewhere in our universe. The study of interstellar organic (carbon-containing) chemistry, which Webb opened up in a new way, is an area of great interest to many astronomers.
CH3+ theorized to be very important because it easily reacts with various other molecules. In effect, it acts like a “railroad station” in that a molecule can last a few moments before going in one of many different directions to react with other molecules. Because of this property, scientists suspect that CH3+ form the basis of interstellar organic chemistry.
Webb’s unique capabilities make it the ideal observatory for searching for these important molecules. Webb’s excellent spatial and spectral resolution, as well as his sensitivity, all contributed to the team’s success. In particular, Webb’s detection of a series of major emission paths from CH3+ confirmed the discovery.
“This detection not only validates Webb’s extraordinary sensitivity but also confirms the importance of the postulated CH3+ in interstellar chemistry,” said Marie-Aline Martin-Drumel of the University of Paris-Saclay in France, a member of the science team.
Although the star in d203-506 is a small red dwarf, its system is bombarded by intense ultraviolet (UV) light from a nearby hot, massive, young star. Scientists believe that most planet-forming disks go through periods of very intense UV radiation, because stars tend to form in clusters that often consist of massive UV-emitting stars.
Usually, UV radiation is expected to destroy complex organic molecules, in this case CH was found3+ may seem like a surprise. However, the team predicts that UV radiation may actually provide the necessary energy source for CH3+ to form in the first place. Once formed, it then drives additional chemical reactions to build more complex carbon molecules.
In general, the team noted that the molecules they saw in d203-506 were very different from the typical protoplanetary disk. Specifically, they couldn’t detect any signs of water.
“This clearly shows that ultraviolet radiation can completely change the chemistry of the protoplanetary disk. It may actually have played an important role in the early chemical stages of the origin of life,” explained Olivier Berné of the French National Center for Scientific Research in Toulouse, lead author of the study.
