Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New evidence for organic compounds in deep space

19.04.2002


The mysterious spectral bands in the infrared of interstellar gas clouds in deep space originate from organic compounds. Research by the Nijmegen physicist Hans Piest confirms this. He has provided new experimental evidence for this almost 30-year-old problem in astronomy.



Each molecule has specific wavelengths at which it can either absorb or emit light. This forms the fingerprint of a substance. With this fingerprint, astronomers can demonstrate the presence of a substance in a distant star or cloud. In a wide range of lines of sight, in the almost empty interstellar space, bright infrared emission is observed, the spectrum of which has become commonly known as the “Unidentified Infrared Bands”. The most widely accepted hypothesis is that complex organic compounds cause the bands. Put more precisely it is thought to be a mixture of various polyaromatic hydrocarbons, each containing about fifty carbon atoms. Nobody had yet succeeded in measuring the spectrum of these complex molecules under conditions comparable to the cold gas situation in deep space where these spectra are found. In deep space the molecules are so far apart that they no longer collide with each other. Collisions dramatically influence the spectrum. It is difficult to create a collision-free situation in the laboratory. Furthermore, the substance is so rarefied that a spectrum can scarcely be measured. Hans Piest found a way of measuring the spectrum indirectly. For this he made use of a special laser from the Institute for Plasma Physics (FOM) in Rijnhuizen. It is a free-electron laser which can produce every desired wavelength between 5 and 250 microns. There are only a few examples of this type of laser in the world. The physicist synthesised polyaromatic hydrocarbons and bound each of these molecules to a noble gas atom. This can only be done at a temperature just above absolute zero. The bonding energy of noble gas atoms is so small that it scarcely affects the spectrum. In order to investigate which wavelengths this complex can absorb he bombarded its with laser light, using a different wavelength for each bombardment. The light from this laser is sufficient to disassociate the weakly bound noble gas molecule from the organic compound. A sensitive mass spectrometer was able to determine whether the organic substance was produced as a function of the infrared wavelength. The physicist used various noble gas atoms and repeatedly obtained the same spectrum. This strongly indicates that the noble gas did not disrupt the spectrum. The spectra measured strongly agreed with previously disputed measurements from NASA. They had directly determined the very weak absorption spectrum of various sorts of polyaromatic hydrocarbons frozen in noble gas ice. These measurements were controversial because the influence of the noble gas ice was difficult to estimate. Now the question still remains as to exactly which polyaromatics are found in space.

Michel Philippens | alphagalileo

More articles from Physics and Astronomy:

nachricht APEX takes a glimpse into the heart of darkness
25.05.2018 | Max-Planck-Institut für Radioastronomie

nachricht First chip-scale broadband optical system that can sense molecules in the mid-IR
24.05.2018 | Columbia University School of Engineering and Applied Science

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: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>