The faint radiation was emitted by the first stars

Jun 8, 2012 07:26 GMT  ·  By
These two panels show the same slice of sky in the constellation Boötes, dubbed the "Extended Groth Strip." The area covered is about 1 by 0.12 degrees
   These two panels show the same slice of sky in the constellation Boötes, dubbed the "Extended Groth Strip." The area covered is about 1 by 0.12 degrees

According to astronomers who have recently used the NASA Spitzer Space Telescope for a new series of investigations, it may be that the observatory has identified the faint glow produced by the very first objects ever to form in the Universe following the Big Bang.

The event took place roughly 13.75 billion years ago, but it took matter a while to cool down to levels where it could support the formation of complex structure. It is estimated that the first stars appeared more than 300 million years later.

Though these stars were most likely extremely massive, only a faint, lumpy glow reaches our planet today, all these eons later. On the other hand, it could be that the light signature does not belong to stars at all, but to extremely hungry black holes.

Due to the phenomenally large distances involved, Spitzer is unable to see individual signature. Rather, it observed the collective pattern of their infrared (IR) light emissions, as shown in the image to the left.

One of the most significant implications of the new study is that the earliest radiation sources were very numerous – something that was never established for certain until now – and that they tended to burn through vast amounts of hydrogen gas at very rapid paces.

The extremely remote pattern of light is known as the cosmic infrared background (CIB), and it is somewhat similar to the more famous cosmic microwave background (CMB). Spitzer was the first to find telltale signs of the CIB, more than 7 years ago.

Details of the new study appear in a paper published in the latest issue of the esteemed Astrophysical Journal. NASA Goddard Space Flight Center investigator Alexander Kashlinsky was the lead author.

“These objects would have been tremendously bright. We can't yet directly rule out mysterious sources for this light that could be coming from our nearby Universe, but it is now becoming increasingly likely that we are catching a glimpse of an ancient epoch,” he explains.

The researcher and his team analyzed two patches of the night sky for this research, for more than 400 hours each. “Spitzer is laying down a roadmap for NASA's upcoming James Webb Telescope, which will tell us exactly what and where these first objects were,” Kashlinsky explains.

“We can gather clues from the light of the universe's first fireworks. This is teaching us that the sources, or the "sparks," are intensely burning their nuclear fuel,” he concludes.