Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rotating ring of complex organic molecules discovered around newborn star

28.06.2016

Chemical diversity in planet forming regions unveiled

Astronomers have long known that organic molecules form in diffuse gas clouds floating between stars. It is thought that as the Solar System formed 4.6 billion years ago, some of these organic molecules were transported from interstellar space to the planet forming disk.


(Upper panel) A schematic illustration of the infalling gas around the protostar. A disk structure with a radius of about 50 AU exists around the protostar. The disk in turn is surrounded by an envelope of gas extended over a 200 AU scale. OCS exists in the envelope gas, while methyl formate mainly exists in the boundary area between the envelope gas and the disk structure. (Lower left) Intensity distribution of methyl formate (HCOOCH3) observed with ALMA. A structure elongated along A-B can be seen centered on the position of the protostar. Methyl formate is located within 50 AU from the protostar.

(Lower right) Intensity distribution of OCS (carbonyl sulfide) observed with ALMA. A structure elongated along A-B can be seen centered on the position of the protostar position, similar to the case of OCS. However the distribution of OCS (~200 AU) is more extended than that of methyl formate.

Credit: ALMA (ESO/NAOJ/NRAO), Oya et al.

Later, these molecules played important roles in the chemical evolution resulting in the emergence of life on the Earth. However, it is still unknown what kinds and quantities of organic molecules were actually supplied from interstellar space.

Although radio astronomy observations during the last decade showed that saturated complex organic molecules, such as methanol (CH3OH) and methyl formate (HCOOCH3) [1], exist around Solar-type protostars, their distributions were too compact to be resolved with the radio telescopes available at the time.

With ALMA, an international team lead by Yoko Oya, a graduate student of Department of Physics, The University of Tokyo, and Nami Sakai, an associate chief scientist of RIKEN, studied the distribution of various organic molecules around a Solar-type protostar IRAS 16293-2422A at a high spatial resolution. They discovered a ring structure of complex organic molecules around the protostar.

The radius of the ring is 50 times wider than the Earth's orbit. This size is comparable to the size of the Solar System, and the ring structure most likely represents the boundary region between infalling gas and a rotating disk structure around the protostar.

The observations clearly showed the distribution of large organic molecules methyl formate (HCOOCH3) and carbonyl sulfide (OCS). Apparently the distribution of methyl formate is confined in a more compact area around the protostar than the OCS distribution, which mainly traces the infalling gas.

"When we measured the motion of the gas containing methyl formate by using the Doppler effect," said Oya "we found a clear rotation motion specific to the ring structure." In this way, they identified the rotating ring structure of methyl formate, although it is not resolved spatially. A similar ring structure is also found for methanol.

These saturated organic molecules are formed in interstellar space and are preserved on the surfaces of dust grains. Around the outer boundary of the disk structure, they evaporate due to shock generated by collisions of the disk and infalling material, and/or due to heating by the light from the baby star. This result is the first direct evidence that interstellar organic materials are indeed fed into the rotating disk structure that eventually forms a planetary system.

In 2014, the team found a similar ring structure of SO (sulfur monoxide) around another Solar-type protostar L1527. In this source, unsaturated complex organic molecules such as CCH and cyclic-C3H2 are very abundant in the infalling gas, while SO preferentially exists in the boundary between the infalling gas and the disk structure.

Although the physical structure in L1527 is similar to that found in IRAS 16293-2422A, the chemical composition is much different. Saturated complex organic molecules are almost completely absent in L1527. The present result, taken together with previous results on L1527, clearly demonstrates for the first time that the materials delivered to a planetary system differ from star to star. A new perspective on chemical composition is thus indispensable for a thorough understanding of the origin of the Solar System and the origin of life on the Earth.

###

Note.

[1] Organic molecules without multiple bonds between atoms are collectively called saturated molecules. On the other hand, molecules with multiple bonds are called unsaturated molecules.

Media Contact

Dr. Masaaki Hiramatsu
hiramatsu.masaaki@nao.ac.jp
81-422-343-630

http://www.nins.jp/english/ 

Dr. Masaaki Hiramatsu | EurekAlert!

More articles from Physics and Astronomy:

nachricht Space radiation won't stop NASA's human exploration
18.10.2017 | NASA/Johnson Space Center

nachricht Study shows how water could have flowed on 'cold and icy' ancient Mars
18.10.2017 | Brown University

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Osaka university researchers make the slipperiest surfaces adhesive

18.10.2017 | Materials Sciences

Space radiation won't stop NASA's human exploration

18.10.2017 | Physics and Astronomy

Los Alamos researchers and supercomputers help interpret the latest LIGO findings

18.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>