Washington, May 26 : Space scientists are using a unique specialized facility, called the Cosmic Simulation Chamber (COSmIC) - that can recognize the molecular structure of particles in space - to track unidentified matter seen for the last century absorbing certain wavelengths of light from distant stars.

Astronomers suspect that one family of carbon-containing compounds, called polycyclic aromatic hydrocarbons (PAHs), is the long-sought matter that produces holes in astronomical observations from multiple wavelengths.

Researchers compared laboratory data of PAHs, measured in this unique facility that simulates space-like conditions, with an extensive set of high-resolution optical astronomical data. With this approach, they were able to survey the mysterious spectral signatures seen in both light absorption and emission that are common throughout interstellar space and determine the abundance of PAHs.

"It is important to understand how PAHs absorb stellar radiation, and how they emit it back, because it contributes to the global energy balance in space," said Farid Salama, a space science researcher in the Astrophysics Branch at Ames.

The research helps solve a problem scientists have struggled with for most of the century. They have detected more than 500 interstellar absorption lines in the spectra (range of frequencies or color) of starlight approaching the Earth. Absorption lines are discrete colors of light absorbed by intervening matter; this absorption leaves holes or "lines" in the spectra. The lines are called diffuse interstellar band (DIBs).

The research will be presented at the American Astronomical Society meeting in Boston, Mass. (ANI)