Space

October 26, 2012

NASA’s Spitzer sees light of lonesome stars

nasa-spitzer
NASA/JPL-Caltech image 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, which is shown in this artist's concept.

A new study using data from NASA’s Spitzer Space Telescope suggests a cause for the mysterious glow of infrared light seen across the entire sky. It comes from isolated stars beyond the edges of galaxies.

These stars are thought to have once belonged to the galaxies before violent galaxy mergers stripped them away into the relatively empty space outside of their former homes.

“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.”

The findings disagree with another theory 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, Md., proposed in June this light, which appears in Spitzer images as a blotchy pattern, is coming from the very first stars and galaxies.

In the new study, Cooray and colleagues looked at data from a larger portion of the sky, called the Bootes field, covering an arc equivalent to 50 full Earth moons. These observations were not as sensitive as those from the Kashlinsky group’s studies, but the larger scale allowed researchers to better analyze the pattern of the background infrared light.

“We looked at the Bootes field with Spitzer for 250 hours,” said co-author Daniel Stern of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “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.”

The team concluded the light pattern of the infrared glow is not consistent with theories and computer simulations of the first stars and galaxies. Researchers say the glow is too bright to be from the first galaxies, which are thought not to have been as large or as numerous as the galaxies we see around us today. Instead, the scientists propose a new theory to explain the blotchy light, based on theories of “intracluster” or “intrahalo” starlight.

Theories predict a diffuse smattering of stars beyond the halos, or outer reaches, of galaxies, and in the spaces between clusters of galaxies. The presence of these stars can be attributed to two phenomena. Early in the history of our universe as galaxies grew in size, they collided with other galaxies and gained mass. As the colliding galaxies became tangled gravitationally, strips of stars were shredded and tossed into space. Galaxies also grow by swallowing smaller dwarf galaxies, a messy process that also results in stray stars.

“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.”

More research is needed to confirm this sprinkling of stars makes up a significant fraction of the background infrared light. For instance, it would be necessary to find a similar pattern in follow-up observations in visible light. NASA’s upcoming James Webb Space Telescope might finally settle the matter for good.

“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.”

Other authors include Joseph Smidt, Francesco De Bernardis, Yan Gong and Christopher C. Frazer of UC Irvine; Matthew L. N. Ashby of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass; Peter R. Eisenhardt of JPL; Anthony H. Gonzalez of the University of Florida in Gainesville; Christopher S. Kochanek of Ohio State University in Columbus; Szymon Kozlowski of Ohio State and the Warsaw

University Observatory in Poland; and Edward L. Wright of the University of California, Los Angeles.

JPL manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology (Caltech) in Pasadena. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.




All of this week's top headlines to your email every Friday.


 
 

 

Headlines December 19, 2014

News: SpaceX’s attempt to land rocket on floating barge postponed - It’s set to be one of the most groundbreaking moments in humanity’s six decades of space exploration. Obama signs $1.1 trillion spending bill into law - President Obama signed the $1.1 trillion federal spending measure into law Dec. 16, officially ending any threat of a government...
 
 

News Briefs December 19, 2014

Trial set for ex-Navy engineer in military secrets case A former Navy civilian engineer is scheduled to stand trial next summer on charges of trying to steal aircraft carrier schematics. Media outlets report that 35-year-old Mostafa Awwad of Yorktown, Va., pleaded not guilty Dec. 17 to two counts of attempted exportation of defense articles and...
 
 
Army photograph by C. Todd Lopez

Army to launch cruise missile-detecting aerostat at Aberdeen Proving Ground

Army photograph by C. Todd Lopez The Army plans to launch an aerostat, part of the “Joint Land Attack Cruise Missile Defense Elevated Netted Sensor,” in late December 2014. The JLENS aerostat will be tethered to the...
 

 
Air Force photograph by SrA. Jordan Castelan

AF delivers Iraqi F-16s for training in US

Air Force photograph by SrA. Jordan Castelan Iraqi air force captain Hama conducts preflight inspections while inside a new to service Iraqi F-16 Fighting Falcon Dec. 17, 2014, located at the nearby Tucson International Airport...
 
 
Air Force photograph by SSgt. Derek VanHorn

Short-notice: A new way to exercise

Air Force photograph by SSgt. Derek VanHorn Airmen from Kadena Air Base, Japan, prepare for an aeromedical evacuation exercise on a KC-135 Stratotanker Dec. 5, 2014, at Misawa Air Base, Japan. The operation was executed in supp...
 
 
Lockheed Martin photograph by Andy Wolfe

Japan, Australia to provide F-35 maintenance sites in Pacific region

Lockheed Martin photograph by Andy Wolfe An F-35C Lightning II joint strike fighter carrier variant prepares to launch from the aircraft carrier USS Nimitz in the Pacific Ocean, Nov. 6, 2014. Japan and Australia will be sharing...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>