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 Columbia engineers create artificial graphene in a nanofabricated semiconductor structure
13.12.2017 | Columbia University School of Engineering and Applied Science

nachricht Long-lived storage of a photonic qubit for worldwide teleportation
12.12.2017 | Max-Planck-Institut für Quantenoptik

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: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Gecko adhesion technology moves closer to industrial uses

13.12.2017 | Information Technology

Columbia engineers create artificial graphene in a nanofabricated semiconductor structure

13.12.2017 | Physics and Astronomy

Research reveals how diabetes in pregnancy affects baby's heart

13.12.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>