A team of astronomers have reportedly solved one of astronomy’s most persistent problems: where does all of the infrared light come from?
The University of California at Irvine study, which utilized data from NASA’s Spitzer Space Telescope, finds that the persistent infrared light seen across the entire night sky is the result of stars found just beyond the edge 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 galaxies.
“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. “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 question of where the infrared glow comes from has long puzzled scientists. When examining the cosmos, astronomers detect a mysterious, sandpaper-like smatterings of light, which Edward L. (Ned) Wright from UCLA refers to as “fluctuations.” The fluctuation of light had left astronomers attempting to calculate the amount of matter needed to produce such light, leaving them with
In the study, Cooray and colleagues looked at data from a larger portion of the sky, called the Bootes field, covering an arc equivalent to fifty full Earth moons. These observations were not as sensitive as those from the Kashlinsky group’s studies, but the larger scale allowed researchers to analyze better 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.”
It remains unclear whether the team of astronomers will launch an additional study in order to confirm their findings. NASA, the U.S. space agency tasked with studying dark matter and all things space, has steadily increased its focus on deciphering the mysteries of dark matter and its role within the universe.
The study was published in the journal Nature.