05Nov2012

Spitzer Spots Lonesome Stars.

New research from scientists using NASA's Spitzer Space Telescope suggests that a mysterious infrared glow across our whole sky is coming from stray stars torn from galaxies. When galaxies grow, they merge and become gravitationally tangled in a violent process that results in streams of stars being ripped away from the galaxies. Such streams, called tidal tails, can be seen in this artist's concept. Scientists say that Spitzer is picking up the collective glow of stars such as these, which linger in the spaces between galaxies. Image credit: NASA/JPL-Caltech/UC Irvine

There’s something strange going on out there. It’s a mysterious glow of infrared light and it is seen across the entire sky. No one has been too sure of what is causing it.Well,  the NASA Spitzer Space Telescope has a suggestion. It just might be some stars that once belonged to galaxies before mergers threw them out into the vast sea of space.  “The infrared background glow in our sky has been a huge mystery,” said Asantha Cooray of the University of California at Irvine, lead author of the new research published in the journal Nature.

“We have new evidence this light is from the stars that linger between galaxies. Individually, the stars are too faint to be seen, but we think we are seeing their collective glow.”

However, these new findings conflict with other theories explaining the same background infrared light observed by Spitzer. A group led by Alexander “Sasha” Kashlinsky of NASA’s Goddard Space Flight Center in Greenbelt, Maryland., proposed in June this light, which appears in Spitzer images as a smeared, blotchy pattern may have been caused by intial stars and galaxies. In the new study, Cooray and associates review data from a larger section of sky known as the Bootes field.

This area covers an arc size of about 50 full Moons. While these observations weren’t as specific as the ones from Kashlinsky’s study, the larger field did allow researchers to better analyze the pattern of the background infrared glow.

“We looked at the Bootes field with Spitzer for 250 hours,” said co-author Daniel Stern of NASA’s Jet Propulsion Laboratory in Pasadena, California. “Studying the faint infrared background was one of the core goals of our survey, and we carefully designed the observations in order to directly address the important, challenging question of what causes the background glow.”

Artist's impression of the James Webb Space Te...

Artist's impression of the James Webb Space Telescope (Photo credit: Wikipedia)

Through the use of this new simulation, the team reached the conclusion the infrared light isn’t consistent with primordial stars and galaxies – it’s just too bright. Instead, the scientists propose a new theory to explain the blotchy light, based on theories of “intracluster” or “intrahalo” starlight.

According to theory, there should be a diffuse pattern of stars beyond the galactic halo and located between galaxy clusters. These stars could be the product of two processes – either as leftovers from galaxy collisions or stray stars leftover from a tidal stripping event.

“A light bulb went off when reading some research papers predicting the existence of diffuse stars,” Cooray said. “They could explain what we are seeing with Spitzer.”

While more research is still needed to solidify the theories, such as those done in visible light, it’s a task which might eventually fall into the realms of those done by the James Webb Space Telescope.

“The keen infrared vision of the James Webb Telescope will be able to see some of the earliest stars and galaxies directly, as well as the stray stars lurking between the outskirts of nearby galaxies,” said Eric Smith, JWST’s deputy program manager at NASA Headquarters in Washington. “The mystery objects making up the background infrared light may finally be exposed.”

Original Story Source: JPL/NASA News Release. Submitted by Tammy Plotner for “Dave Reneke’s World of Space and Astronomy News”.

Read previous post:
Meteorite
Rare 300kg Meteorite Unearthed in Poland

Rare 300kg Meteorite Unearthed in Poland The largest meteorite ever...

Sky
Six Strange Things That Fell From The Sky

6 Surprising Things Falling From The Sky Stories of strange...

Jobs
Future Jobs in Space

Help Wanted: Future Jobs in Space. As the first SpaceX...

Close