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
On Mars, sands shift to a different drum
24.05.2019 | University of Arizona
New Boost for ToCoTronics
23.05.2019 | Julius-Maximilians-Universität Würzburg
A new assessment of NASA's record of global temperatures revealed that the agency's estimate of Earth's long-term temperature rise in recent decades is accurate to within less than a tenth of a degree Fahrenheit, providing confidence that past and future research is correctly capturing rising surface temperatures.
The most complete assessment ever of statistical uncertainty within the GISS Surface Temperature Analysis (GISTEMP) data product shows that the annual values...
Physicists at the University of Basel are able to show for the first time how a single electron looks in an artificial atom. A newly developed method enables them to show the probability of an electron being present in a space. This allows improved control of electron spins, which could serve as the smallest information unit in a future quantum computer. The experiments were published in Physical Review Letters and the related theory in Physical Review B.
The spin of an electron is a promising candidate for use as the smallest information unit (qubit) of a quantum computer. Controlling and switching this spin or...
Engineers at the University of Tokyo continually pioneer new ways to improve battery technology. Professor Atsuo Yamada and his team recently developed a...
With a quantum coprocessor in the cloud, physicists from Innsbruck, Austria, open the door to the simulation of previously unsolvable problems in chemistry, materials research or high-energy physics. The research groups led by Rainer Blatt and Peter Zoller report in the journal Nature how they simulated particle physics phenomena on 20 quantum bits and how the quantum simulator self-verified the result for the first time.
Many scientists are currently working on investigating how quantum advantage can be exploited on hardware already available today. Three years ago, physicists...
'Quantum technologies' utilise the unique phenomena of quantum superposition and entanglement to encode and process information, with potentially profound benefits to a wide range of information technologies from communications to sensing and computing.
However a major challenge in developing these technologies is that the quantum phenomena are very fragile, and only a handful of physical systems have been...
29.04.2019 | Event News
17.04.2019 | Event News
15.04.2019 | Event News
24.05.2019 | Physics and Astronomy
24.05.2019 | Medical Engineering
24.05.2019 | Life Sciences