NASA's Spitzer Space Telescope Uncovers Patterns of Light From First Stars and Galaxies

Posted on June 10, 2012

Astronomers have uncovered patterns of light that appear to be from the very first stars and galaxies that formed in the universe. The light patterns were hidden within a strip of sky observed by NASA's Spitzer Space Telescope. The two panels show the same slice of sky in the constellation Bootes, dubbed the Extended Groth Strip. You can see a much larger version of the image here. Astronomers say the observations help confirm the first objects were numerous in quantity and furiously burned cosmic fuel.

Alexander "Sasha" Kashlinsky of NASA's Goddard Space Flight Center in Greenbelt, Md., lead author of a new paper appearing in The Astrophysical Journal, says, "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."

Spitzer first caught hints of this remote pattern of light, known as the cosmic infrared background, in 2005, and again with more precision in 2007. Spitzer is now in the extended phase of its mission and is performing in-depth studies on specific patches of the sky. Kashlinsky and his colleagues used Spitzer to look at two patches of sky for more than 400 hours each. The team then carefully subtracted all the known stars and galaxies in the images. Rather than being left with a black, empty patch of sky, they found faint patterns of light.

Kashlinsky likens the observations to looking for Fourth of July fireworks in New York City from Los Angeles. First, you would have to remove all the foreground lights between the two cities, as well as all the lights of New York City itself. You would ultimately be left with a fuzzy map of how the fireworks are distributed, but they would still be too distant to make out individually.

Kashlinsky says, "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."

Kashlinsky also says, "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."

Glenn Wahlgren, Spitzer program scientist at NASA Headquarters in Washington, says, "This is one of the reasons we are building the James Webb Space Telescope. Spitzer is giving us tantalizing clues, but James Webb will tell us what really lies at the era where stars first ignited."

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