Bleach discovered in space

Astronomers find key molecule hydrogen peroxide with the APEX Telescope in Chile

July 08, 2011

Rho Ophiuchi would have been a gold mine for hairdressers. Astronomers have now detected molecules of hydrogen peroxide for the first time in this stellar nursery 400 light years away. This liquid compound of hydrogen and oxygen is used to bleach hair. The researchers are interested in another aspect, however. How does water, life's most important molecule, form in interstellar space?

Hydrogen peroxide (symbol H2O2) is familiar to chemists, cleaning staff and hairdressers for its bleaching properties. This whitener and antiseptic has now become one of the many familiar molecules discovered not only on Earth but also in interstellar space. An international team of astronomers carried out its observations with APEX (Atacama Pathfinder Experiment), the submillimetre telescope on the 5000-metre Chajnantor plateau in the Chilean Andes which is operated jointly by the Max Planck Institute for Radio Astronomy in Bonn together with the Swedish Onsala Space Observatory and the European Southern Observatory.

The region observed is close to the star Rho Ophiuchi in the serpent bearer constellation and contains extremely cold (minus 250 degrees Celsius), dense clouds of gas and dust in which new stars are being born. These clouds are mostly made of hydrogen, but also contain traces of other chemicals, and are thus prime targets for astronomers hunting for molecules in interstellar space.

As they scoured the region, the astronomers identified the characteristic signature of hydrogen peroxide in the radio emissions. "This proof is a really exciting result,” says Per Bergman, astronomer at Onsala Space Observatory in Sweden. “From laboratory experiments we already knew precisely which wavelengths to look for, but there is just one of these molecules for every ten billion hydrogen molecules.

Hydrogen peroxide (H2O2) is a key molecule for both astronomers and chemists. Its formation is closely linked to two other very familiar molecules, oxygen and water. Both are indispensable for life as we know it on Earth. Since much of the water on our planet is thought to have originally formed in space, the scientists are keen to understand how it is created.

Hydrogen peroxide is thought to form in space on the surfaces of cosmic dust grains - very fine particles similar to sand and soot - atomic hydrogen (H) is added to oxygen molecules (O2). A further chemical reaction between the hydrogen peroxide and more hydrogen can lead to the formation of water (H2O).

"We don't yet know how some of the most important molecules here on Earth are formed in space,” says Bérengère Parise, head of the Emmy Noether research group on star formation and astrochemistry at the Max Planck Institute for Radio Astronomy in Bonn, “but our discovery of hydrogen peroxide seems to be showing us that cosmic dust is the missing ingredient we have been looking for.”

To work out how exactly the formation processes of these important molecules can be intertwined will need more observations of Rho Ophiuchi and other star-forming regions with the telescopes of the future such as ALMA (Atacama Large Millimeter Array) which is also currently being built on the Chajnantor plateau - and help from chemists in laboratories on Earth.

 

******************

 

The team comprised Per Bergman (Onsala Space Observatory, Chalmers University of Technology, Onsala, Sweden), Bérengère Parise (Max Planck Institute for Radio Astronomy, Bonn, Germany), Robert Liseau (Chalmers University of Technology, Onsala, Sweden), Bengt Larsson (Stockholm University, Sweden), Hans Olofsson (Onsala Space Observatory, Chalmers University of Technology, Onsala, Sweden), Karl M. Menten and Rolf Güsten (both Max Planck Institute for Radio Astronomy, Bonn).

The Atacama Pathfinder Experiment (APEX) is a collaboration between the Max Planck Institute for Radio Astronomy (MPIfR), Onsala Space Observatory (OSO), and the European Southern Observatory (ESO) to construct and operate a modified prototype antenna of ALMA (Atacama Large Millimetre Array) as a single dish on the Chajnantor plateau at an altitude of 5,100 meters above sea level (Atacama Desert, Chile). The telescope was manufactured by VERTEX Antennentechnik in Duisburg, Germany. The operation of the telescope is entrusted to ESO.

The Emmy Noether Programme of the German Research Foundation (DFG) supports young researchers in achieving independence at an early stage of their scientific careers. Young postdocs gain the qualifications required for a university teaching career during a DFG-funded period, usually lasting five years, in which they lead their own independent junior research group.

NJ / HOR

Go to Editor View