Put an Argon surprise
Molecules are containing noble gas in space. It is the first time that such a presence is detected. It was done by a team of astronomers from the University College London (UCL), finding in the Crab Nebula, the remains of a supernova in the constellation Taurus..
Led by Mike Barlow from Department of Physics and Astronomy at UCL, the researchers used data obtained with the ESA Herschel observation satellite, which operated in the infrared. The measurements to be carried out of their cold gas and dust in the region observed they led to the serendipitous discovery of the fingerprint of the chemical hydride ion of argon. The results of their research were published this week in the Sciencemagazine.
The discovery confirms the scientific theories such as argon is formed in nature.
“We were conducting a ‘survey’ of dust in many bright supernova remnants using the Herschel data, including those of the Crab Nebula,” says Mike Barlow. “The presence of hydride ions of argon was totally unexpected, because you do not expect that a noble gas such as argon can form molecules, and you would not expect to find them in a hostile environment such as the remains of a supernova.”
The researchers have used the instrument SPIRE Herschel to make a spectroscopic observation of the remains of supernovae, so as to separate the infrared light waves in their different lengths, as well as a prism separates white light into the respective colors of the iris. After analyzing the effects, the team of astronomers has seen unusual characteristics that have taken time to be fully understood.
“Look in the infrared spectrum – adds Barlow – it is useful to find the signature of the molecules, in particular the signature of their rotation. It is so specific that can be detected in the infrared light from our telescopes.”
The Crab Nebula is the remnant of the famous supernova that exploded in 1054 and was recorded by Chinese astronomers.
“The intense radiation inside the nebula – says Sergio Molinari INAF- IAPS, Principal Investigator of the project, increased observation of Herschel – argon ionizes the hydrogen, thus allowing the formation of the molecules and the ArH + his revelation in line in the far infrared, at 243 and 486 microns, with the SPIRE instrument on board the satellite HERSCHEL. The fundamental aspect is that the observation of Argon in the form of the molecule with hydrogen allows revealing also what kind of isotopeis,i.e. by its atomic weight, and that is the quantity of protons and neutrons in its nucleus. The isotope of Argon revealed in the Crab is the Argon -36, and this discovery finally allows us to confirm the theories that were predicted that the Argon space was created mainly during the very brief and intense phase of nuclear fusion during the explosions of supernovae, and exactly in the ‘version’ with 36 nucleons. The isotope of argon that we find in Earth’s atmosphere is argon -40, produced by the decay of radioactive potassium in the rocks.”
“It’s a discovery – adds the INAF researcher – which comes after more than 6 months after the end of the mission HERSCHEL. By analyzing the spectra obtained with the SPIRE we have realized that in addition to the expected chemical species were also revealed lines at frequencies totally unexpected. We hunted the chemical species responsible, which finally led to the identification of ArH +. This is certainly not the only line not yet identified in the spectra that Herschel has acquired during his four years of life, the data store of Herschel is a goldmine from which we expect great discoveries for many years to come.”