생명의 기원을 찾는 핵심 발견 – 천문학자들은 우주 ‘먼지 덫’에서 가장 큰 분자를 발견합니다

Atacama 대형 밀리미터/미터 매트릭스 사용([{” attribute=””>ALMA) in Chile, researchers at Leiden Observatory in the Netherlands have for the first time detected dimethyl ether in a planet-forming disc. With nine atoms, this is the largest molecule identified in such a disc to date. It is also a precursor of larger organic molecules that can lead to the emergence of life.

This composite image features an artistic impression of the planet-forming disc around the IRS 48 star, also known as Oph-IRS 48. The disc contains a cashew-nut-shaped region in its southern part, which traps millimeter-sized dust grains that can come together and grow into kilometer-sized objects like comets, asteroids, and potentially even planets. Recent observations with the Atacama Large Millimeter/submillimeter Array (ALMA) spotted several complex organic molecules in this region, including dimethyl ether, the largest molecule found in a planet-forming disc to date. The emission signaling the presence of this molecule (real observations shown in blue) is clearly stronger in the disc’s dust trap. A model of the molecule is also shown in this composite. Credit: ESO/L. Calçada, ALMA (ESO/NAOJ/NRAO)/A. Pohl, van der Marel et al., Brunken et al.

“From these results, we can learn more about the origin of life on our planet and therefore get a better idea of the potential for life in other planetary systems. It is very exciting to see how these findings fit into the bigger picture,” says Nashanty Brunken, a Master’s student at Leiden Observatory, part of Leiden University, and lead author of the study published on March 8, 2022, in Astronomy & Astrophysics.

생명체의 구성 요소는 행성에서 어떻게 끝나나요? 행성 형성 원반에서 발견된 가장 큰 분자의 발견은 이에 대한 단서를 제공합니다. 신용 거래:[{” attribute=””>ESO

Dimethyl ether is an organic molecule commonly seen in star-forming clouds, but had never before been found in a planet-forming disc. The researchers also made a tentative detection of methyl formate, a complex molecule similar to dimethyl ether that is also a building block for even larger organic molecules.

“It is really exciting to finally detect these larger molecules in discs. For a while we thought it might not be possible to observe them,” says co-author Alice Booth, also a researcher at Leiden Observatory.

These images from the Atacama Large Millimeter/submillimeter Array (ALMA) show where various gas molecules were found in the disc around the IRS 48 star, also known as Oph-IRS 48. The disc contains a cashew-nut-shaped region in its southern part, which traps millimeter-sized dust grains that can come together and grow into kilometer-sized objects like comets, asteroids and potentially even planets. Recent observations spotted several complex organic molecules in this region, including formaldehyde (H2CO; orange), methanol (CH3OH; green), and dimethyl ether (CH3OCH3; blue), the last being the largest molecule found in a planet-forming disc to date. The emission signaling the presence of these molecules is clearly stronger in the disc’s dust trap, while carbon monoxide gas (CO; purple) is present in the entire gas disc. The location of the central star is marked with a star in all four images. The dust trap is about the same size as the area taken up by the methanol emission, shown on the bottom left. Credit: ALMA (ESO/NAOJ/NRAO)/A. Pohl, van der Marel et al., Brunken et al.

The molecules were found in the planet-forming disc around the young star IRS 48 (also known as Oph-IRS 48) with the help of ALMA, an observatory co-owned by the European Southern Observatory (ESO). IRS 48, located 444 light-years away in the constellation Ophiuchus, has been the subject of numerous studies because its disc contains an asymmetric, cashew-nut-shaped “dust trap.” This region, which likely formed as a result of a newly born planet or small companion star located between the star and the dust trap, retains large numbers of millimeter-sized dust grains that can come together and grow into kilometer-sized objects like comets, asteroids and potentially even planets.

Annotated image from the Atacama Large Millimeter/submillimeter Array (ALMA) showing the dust trap in the disc that surrounds the system Oph-IRS 48. The dust trap provides a safe haven for the tiny dust particles in the disc, allowing them to clump together and grow to sizes that allow them to survive on their own. The green area is the dust trap, where the bigger particles accumulate. The size of the orbit of Neptune is shown in the upper left corner to show the scale. Credit: ALMA (ESO/NAOJ/NRAO)/Nienke van der Marel

Many complex organic molecules, such as dimethyl ether, are thought to arise in star-forming clouds, even before the stars themselves are born. In these cold environments, atoms and simple molecules like carbon monoxide stick to dust grains, forming an ice layer and undergoing chemical reactions, which result in more complex molecules. Researchers recently discovered that the dust trap in the IRS 48 disc is also an ice reservoir, harboring dust grains covered with this ice rich in complex molecules. It was in this region of the disc that ALMA has now spotted signs of the dimethyl ether molecule: as heating from IRS 48 sublimates the ice into gas, the trapped molecules inherited from the cold clouds are freed and become detectable.

이 비디오는 먼지 트랩이 있는 행성으로 구성된 원반으로 둘러싸인 별인 Oph-IRS 48 시스템으로 확대되었습니다. 이 트랩은 먼지 입자가 더 큰 몸체를 성장하고 증식하도록 합니다.

“이를 더욱 흥미롭게 만드는 것은 이러한 더 큰 복잡한 분자가 디스크에서 형성되는 행성을 공급하는 데 사용할 수 있다는 사실입니다.”라고 Booth는 설명합니다. “대부분의 시스템에서 이러한 입자가 얼음 속에 숨겨져 있기 때문에 이것은 이전에 알려지지 않았습니다.”

디메틸 에테르의 발견은 항성 형성 지역에서 일반적으로 발견되는 다른 많은 복잡한 분자가 행성 형성 원반의 얼음 구조에도 숨어 있을 수 있음을 시사합니다. 이 분자는 다음과 같은 프리바이오틱 분자의 전구체입니다.[{” attribute=””>amino acids and sugars, which are some of the basic building blocks of life.

This chart shows the large constellation of Ophiuchus (The Serpent Bearer). Most of the stars that can be seen in a dark sky with the unaided eye are marked. The location of the system Oph-IRS 48 is indicated with a red circle. Credit: ESO, IAU and Sky & Telescope

By studying their formation and evolution, researchers can therefore gain a better understanding of how prebiotic molecules end up on planets, including our own. “We are incredibly pleased that we can now start to follow the entire journey of these complex molecules from the clouds that form stars, to planet-forming discs, and to comets. Hopefully, with more observations we can get a step closer to understanding the origin of prebiotic molecules in our own Solar System,” says Nienke van der Marel, a Leiden Observatory researcher who also participated in the study.

이 비디오는 먼지 트랩이 있는 행성으로 구성된 원반으로 둘러싸인 별인 Oph-IRS 48 시스템으로 확대되었습니다. 이 트랩은 먼지 입자가 더 큰 몸체를 성장하고 증식하도록 합니다.

현재 칠레에서 건설 중이고 10년 후반에 작업을 시작할 예정인 ESO의 ELT(초거대 망원경)를 사용한 IRS 48의 향후 연구를 통해 팀은 지구와 같은 행성이 형성될 수 있는 디스크 내부 영역의 화학을 연구할 수 있을 것입니다. .

참조: “행성 형성 디스크의 주요 비대칭 얼음 덫: III. 디메틸 에테르의 첫 번째 감지” Nasante JC Bronkin, Alice S. Booth, Margot Lemker, Bona Nazari, Ninke van der Marel 및 Ewen F. Van Dyschoek , 2022년 3월 8일, 천문학 및 천체 물리학.
DOI: 10.1051/0004-6361/202142981

이 간행물은 2022년 세계 여성의 날에 발행되었으며 6명의 여성 연구원의 연구가 포함되어 있습니다.

이 팀은 Nashanty GC Brunken(네덜란드 라이덴 대학교 라이덴 천문대)으로 구성되어 있습니다. [Leiden]), 앨리스 S. Booth(라이덴), Margot Lemker(라이덴), Boneh Nazari(라이덴), Ninke van der Marel(라이덴), Ewen F. Van Dyschoek(라이덴 천문대, 막스 플랑크 해외 선교 연구소, Garching, Germany)