September 20, 2012
Astrochemistry Entering New Era As Technologies, Techniques Move Ahead
Lee Rannals for redOrbit.com — Your Universe Online
A new field of chemistry is arising through the development of technologies, and it ensures that scientists do not just set their sights on things of this Earth.
Scientists were able to improve and speed up the process of identifying the "fingerprints" of chemicals in the cosmos through new technology. Unraveling these fingerprints will enable studies that would have been either impossible or prohibitively time-consuming.
"We've shown that, with ALMA, we're going to be able to do real chemical analysis of the gaseous 'nurseries' where new stars and planets are forming, unrestricted by many of the limitations we've had in the past," Anthony Remijan of the National Radio Astronomy Observatory in Charlottesville, VA said in a press release.
ALMA is under construction in the Atacama Desert of northern Chile, and is poised to be completed in 2013. Once it is finished, the telescope will have 66 high-precision antennas and advanced electronics to provide scientists with unprecedented tools to explore the Universe.
The wavelengths at which ALMA will be exploring are rich in clues about the presence of specific molecules in the universe. More than 170 molecules, including organic molecules like sugars and alcohols, have been discovered in space.
"We know that many of the chemical precursors to life exist in these stellar nurseries even before the planets form," Thomas Wilson of the Naval Research Laboratory in Washington, D.C. said in the press release.
Each time a molecule changes from one condition to another, it often emits radio waves at very specific wavelengths. Each molecule has a unique pattern of wavelengths that it emits or absorbs, and that pattern helps scientists identify the molecule.
These individual wavelengths are called spectral lines because of their appearance in plots. A specific chemical is able to produce numerous spectral lines. New technology allows scientists to gather and analyze a broad swath of wavelengths at once.
"We now can take a sample of a chemical, test it in the laboratory, and get a plot of all its characteristic lines over a large range of wavelengths. We get the whole picture at once," Frank DeLucia of the Ohio State University (OSU) said in the release. "We can then model the characteristics of all the lines of a chemical at different temperatures."
The scientists were able to use laboratory data and compare the patterns of suspected molecules with those produced by observing the star-forming region with ALMA.
"The matchup was amazing," said Sarah Fortman, also from OSU. "Spectral lines that had been unidentified for years suddenly matched our laboratory data, verified the existence of specific molecules, and gave us a new tool to attack the complex spectra from regions in our Galaxy."
The first test the researchers did was with ethyl cyanide because it is well established that it already exists in space.
"In the past, there were so many unidentified lines that we called them 'weeds,' and they only confused our analysis," DeLucia said in the release. "Now those 'weeds' are valuable clues that can tell us not only what chemicals are present in these cosmic gas clouds, but also can give important information about the conditions in those clouds."
Suzanna Randall of ESO Headquarters in Garching, Germany said that this is a new era in astrochemistry.
"These new techniques are going to revolutionize our understanding of the fascinating nurseries where new stars and planets are being born," Randall said in the release.
The new techniques are able to be used with other telescopes and laboratories as well, which could ultimately "change the way astrochemists do business," according to Remijan.
The researchers published their findings in the Journal of Molecular Spectroscopy.