Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

First detection of methyl alcohol in a planet-forming disc

16.06.2016

The protoplanetary disc around the young star TW Hydrae is the closest known example to Earth, at a distance of only about 170 light-years. As such it is an ideal target for astronomers to study discs. This system closely resembles what astronomers think the Solar System looked like during its formation more than four billion years ago.

The Atacama Large Millimeter/Submillimeter Array (ALMA - http://www.eso.org/public/teles-instr/alma/) is the most powerful observatory in existence for mapping the chemical composition and the distribution of cold gas in nearby discs. These unique capabilities have now been exploited by a group of astronomers led by Catherine Walsh (Leiden Observatory, the Netherlands) to investigate the chemistry of the TW Hydrae protoplanetary disc.


This artist's impression shows the closest known protoplanetary disc, around the star TW Hydrae in the huge constellation of Hydra (The Female Watersnake). The organic molecule methyl alcohol (methanol) has been found by the Atacama Large Millimeter/Submillimeter Array (ALMA) in this disc. This is the first such detection of the compound in a young planet-forming disc.

Credit: ESO/M. Kornmesser

The ALMA observations have revealed the fingerprint of gaseous methyl alcohol, or methanol (CH3OH), in a protoplanetary disc for the first time. Methanol, a derivative of methane, is one of the largest complex organic molecules detected in discs to date. Identifying its presence in pre-planetary objects represents a milestone for understanding how organic molecules are incorporated into nascent planets.

Furthermore, methanol is itself a building block for more complex species of fundamental prebiotic importance, like amino acid compounds. As a result, methanol plays a vital role in the creation of the rich organic chemistry needed for life.

Catherine Walsh, lead author of the study, explains: "Finding methanol in a protoplanetary disc shows the unique capability of ALMA to probe the complex organic ice reservoir in discs and so, for the first time, allows us to look back in time to the origin of chemical complexity in a planet nursery around a young Sun-like star."

Gaseous methanol in a protoplanetary disc has a unique importance in astrochemistry. While other species detected in space are formed by gas-phase chemistry alone, or by a combination of both gas and solid-phase generation, methanol is a complex organic compound which is formed solely in the ice phase via surface reactions on dust grains.

The sharp vision of ALMA has also allowed astronomers to map the gaseous methanol across the TW Hydrae disc. They discovered a ring-like pattern in addition to significant emission from close to the central star [1].

The observation of methanol in the gas phase, combined with information about its distribution, implies that methanol formed on the disc's icy grains, and was subsequently released in gaseous form. This first observation helps to clarify the puzzle of the methanol ice-gas transition [2], and more generally the chemical processes in astrophysical environments [3].

Ryan A. Loomis, a co-author of the study, adds: "Methanol in gaseous form in the disc is an unambiguous indicator of rich organic chemical processes at an early stage of star and planet formation. This result has an impact on our understanding of how organic matter accumulates in very young planetary systems."

This successful first detection of cold gas-phase methanol in a protoplanetary disc means that the production of ice chemistry can now be explored in discs, paving the way to future studies of complex organic chemistry in planetary birthplaces. In the hunt for life-sustaining exoplanets, astronomers now have access to a powerful new tool.

###

Notes

[1] A ring of methanol between 30 and 100 astronomical units(au) reproduces the pattern of the observed methanol data from ALMA. The identified structure supports the hypothesis that the bulk of the disc ice reservoir is hosted primarily on the larger (up to millimetre-sized) dust grains, residing in the inner 50 au, which have become decoupled from the gas, and drifted radially inwards towards the star.

[2] In this study, rather than thermal desorption (with methanol released at temperatures higher than its sublimation temperature), other mechanisms are supported and discussed by the team, including photodesorption by ultraviolet photons and reactive desorption. More detailed ALMA observations would help to definitely favour one scenario among the others.

[3] Radial variation of chemical species in the disc midplane composition, and specifically the locations of snowlines (http://www.eso.org/public/news/eso1333/) , are crucial for understanding the chemistry of nascent planets.The snowlines mark the boundary beyond which a particular volatile chemical species is frozen out onto dust grains. The detection of methanol also in the colder outer regions of the disc shows that it is able to escape off the grains at temperatures much lower than its sublimation temperature, necessary to trigger thermal desorption.

More information

This research was presented in a paper entitled "First detection of gas-phase methanol in a protoplanetary disk", by Catherine Walsh et al., published in Astrophysical Journal, Volume 823, Number 1.

The team is composed of Catherine Walsh (Leiden Observatory, Leiden University, Leiden, The Netherlands), Ryan A. Loomis (Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA), Karin I. Öberg (Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA), Mihkel Kama (Leiden Observatory, Leiden University, Leiden, The Netherlands), Merel L. R. van't Hoff (Leiden Observatory, Leiden University, Leiden, The Netherlands), Tom J. Millar (School of Mathematics and Physics, Queen's University Belfast, Belfast, UK), Yuri Aikawa (Center for Computational Sciences, University of Tsukuba, Tsukuba, Japan), Eric Herbst (Departments of Chemistry and Astronomy, University of Virginia, Charlottesville, Virginia, USA), Susanna L. Widicus Weaver (Department of Chemistry, Emory University, Atlanta, Georgia, USA) and Hideko Nomura (Department of Earth and Planetary Science, Tokyo Institute of Technology, Tokyo, Japan).

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

ESO is the foremost intergovernmental astronomy organisation in Europe and the world's most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world's largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Links

* Research paper - http://iopscience.iop.org/article/10.3847/2041-8205/823/1/L10/meta

* Earlier ALMA observations of organic compounds in discs - http://www.eso.org/public/news/eso1513/

* Photos of ALMA - http://www.eso.org/public/images/archive/search/?adv=&subject_name=Atacama%20Large%20Millimeter/submillimeter%20Array

* Other press releases featuring ALMA - http://www.eso.org/public/news/archive/search/?adv=&facility=36

Contacts

Catherine Walsh
Leiden Observatory
Leiden University, The Netherlands
Tel: +31 71527 ext 6287
Email: cwalsh@strw.leidenuniv.nl

Richard Hook
ESO Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6655
Cell: +49 151 1537 3591
Email: rhook@eso.org

Richard Hook | EurekAlert!

Further reports about: ALMA ESO Observatory Telescope protoplanetary disc

More articles from Physics and Astronomy:

nachricht Black hole spin cranks-up radio volume
15.01.2018 | National Institutes of Natural Sciences

nachricht The universe up close
15.01.2018 | Georg-August-Universität Göttingen

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: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

Im Focus: Autoimmune Reaction Successfully Halted in Early Stage Islet Autoimmunity

Scientists at Helmholtz Zentrum München have discovered a mechanism that amplifies the autoimmune reaction in an early stage of pancreatic islet autoimmunity prior to the progression to clinical type 1 diabetes. If the researchers blocked the corresponding molecules, the immune system was significantly less active. The study was conducted under the auspices of the German Center for Diabetes Research (DZD) and was published in the journal ‘Science Translational Medicine’.

Type 1 diabetes is the most common metabolic disease in childhood and adolescence. In this disease, the body's own immune system attacks and destroys the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fachtagung analytica conference 2018

15.01.2018 | Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

 
Latest News

Black hole spin cranks-up radio volume

15.01.2018 | Physics and Astronomy

A matter of mobility: multidisciplinary paper suggests new strategy for drug discovery

15.01.2018 | Life Sciences

New method to map miniature brain circuits

15.01.2018 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>