Scientists now have a hint on the source of the puzzling glow of infrared light that radiates from all angles of the galaxy.

It turns out that this faint cosmic light, usually observed by astronomers, are organic molecules known as benzonitriles.  This class of organic molecules composed of carbon, known as polycyclic aromatic hydrocarbons, were observed using the National Science Foundations' Green Bank Telescope.

With the detection, it is likely that similar organic molecules are spread throughout the space. Experts presume that almost 10 percent of all the carbon content in the universe is tied with these organic molecules.

Based on the abstract, the identification of the molecule may be the first step toward the discovery of the composition of aromatic materials within the stellar medium that will eventually be incorporated into new stars and planets. Like many compounds, benzonitrile emits a sweet scent that is usually compared to almond.

"I can tell you from personal experience it smells like almonds," says study author Brett McGuire from the NROA.

Radio Fingerprints Used For Detection

To pinpoint the radiation, scientists used radio astronomy or radio fingerprints to detect the rotational transitions of the benzonitrile chemical compounds. They studied the shape of the molecules through the pattern of light that the benzonitrile absorbs or emits as it rotates.

The atoms of PAHs are arranged in multiple hexagonal rings, making them more difficult to detect. However, the spotted benzonitrile only has one hexagonal ring of carbon and arranged in an asymmetrical pattern. McGuire's team identified nine distinct spikes in the radio spectrum that pertain to the molecule.

Before the discovery, the source of the infrared light is unknown. The emission only appears as a series of spikes in the spectrum that seemed unrelated to any known cosmic objects like interstellar clouds, supernova remnants, and star-forming regions.

Chemists at the National Radio Astronomy Observatory were able to detect the molecule's radio fingerprint while observing the nebula Taurus Molecular Cloud located 430 light years from Earth.

Football Field-Sized Telescope Crucial In The Discovery

McGuire and his team used the giant GBT known as the most accurate large-dish telescope in the world. The dish surface of the GBT measures 2.3 acres, or about the size of a football field.

The receivers of the telescope can cover 100 MHz to 100 GHz frequencies and are used by scientists for chemistry, physics, radar, receiving and astronomy. It can detect even the super faint hydrogen clouds between stars and galaxies.

The results of the study were presented at a meeting of the American Astronomical Society.

ⓒ 2021 All rights reserved. Do not reproduce without permission.