Orion Nebulası'nın hassas izlerinin derinliklerinde, nihayet yıldızlararası uzayda daha önce hiç görülmemiş önemli bir karbon molekülü bulduk.

Methenium, also known as the methyl cation (CH3+), is a carbon compound that has long been predicted to play an important role in organic chemistry in interstellar space. Now, scientists using the James Webb Space Telescope have confirmed the plausibility of this role by detecting this compound in a disc of dust and gas surrounding a baby star.
Although CH3+ is not considered a necessary component for life, scientists believe it helps form more complex carbon molecules. Since life as we know it is carbon-based, the presence of CH3+ in interstellar space has important implications for our understanding of how life might arise elsewhere in the galaxy.

"This detection not only confirms Webb's incredible sensitivity, but also the supposed central importance of CH3+ in interstellar chemistry," says astronomer Marie-Aline Martin-Drumel of the University of Paris-Saclay in France.
CH3+ is a very interesting molecule. It reacts with a wide variety of other molecules, but not with hydrogen, the most abundant element in our universe. This means it has the potential to be a stepping stone on the path to the creation of more complex molecules in interstellar environments - the cornerstone of interstellar carbon-based or organic chemistry, as scientists have believed for decades.

But it has never been seen in observations outside the Solar System, which means we cannot be sure of its presence or role. Most such observations are made in the radio spectrum, but CH3+ lacks the necessary properties to be observed by radio telescopes.
This is where JWST comes in. Its exceptional infrared sensitivity makes it ideal for probing dusty environments where CH3+ is expected to be found, because infrared light can pass through dust where other wavelengths are scattered.
A team led by astronomer Olivier Berné from the University of Toulouse in France took a closer look at the Orion nebula, captured by JWST's mid-infrared spectrometer. There, they found surprising bright lines in the spectrum, which ultimately can best be explained by the presence of CH3+.

The location of this detection was a disc of dust and gas orbiting a red dwarf star called d203-506. This is a common feature of new stars; they are born from a dense knot of material in a molecular cloud that collapses under gravity in space. As this object rotates, it accumulates material arranged in a disc that spins around the emerging star like water around a drain.
After the star forms, what is left of the disc begins to form the other objects that make up a planetary system, such as planets, asteroids, comets and moons. Our Solar System was born from such a disc; studying discs around other stars can help us understand how the Solar System formed and how life arose there.

The protoplanetary disc of d203-506 is intensely irradiated by harsh ultraviolet light from nearby massive stars, and this is thought to be a common stage in the life of protoplanetary discs, since most stars form in stellar nurseries where these massive stars are common. Evidence from meteorites suggests that our Solar System also passed through such a stage.
Such radiation is thought to have a highly destructive effect on complex organic molecules. It has therefore been somewhat puzzling to understand how they survived well enough for life to emerge later.

Fortunately, the team found a solution to this problem. According to their analyses, ultraviolet light promotes the formation of CH3+. Cosmically speaking, ultraviolet radiation doesn't last very long: the massive stars that spew it are short-lived, lasting only a few million years before dying out.
So once the molecule is present and the massive stars are gone, CH3+ can continue to help form more complex carbon molecules.

"This clearly shows that ultraviolet radiation can completely change the chemistry of a proto-planetary disc," says Berné.
"It could actually play a critical role in the early chemical stages of the origin of life by helping to produce CH3+ - something that has perhaps been previously underestimated."
Questions remain about the properties of this molecule and the role it plays in interstellar chemistry. Future research will address them, the team says.

 

Source: https://www.sciencealert.com/