June 6, 2013
Black Holes May Have Been More Abundant In Early Universe
John P. Millis, PhD for redOrbit.com — Your Universe Online
As telescopes peer into the distant background of the Universe they are, in effect, looking back in time. The light emitted from these objects has been traveling across the Universe for perhaps billions of years. So by analyzing the background light of the sky researchers can get a picture of the composition of the Universe early in its evolution.
According to Alexander Kashlinsky, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Md, "Our results indicate black holes are responsible for at least 20 percent of the cosmic infrared background, which indicates intense activity from black holes feeding on gas during the epoch of the first stars."
Data from the Spitzer instrument revealed information about the cosmic infrared background (CIB) — the light that reveals the first large scale structures in the Universe. Because of the great distance individual objects are not resolvable. Instead the integrated flux of infrared light allows astronomers to decipher the relative abundances of stars and black holes.
And coupled with the X-ray data, the nature of the CIB hotspots could be probed. "We wanted to understand the nature of the sources in this era in more detail, so I suggested examining Chandra data to explore the possibility of X-ray emission associated with the lumpy glow of the CIB," said Guenther Hasinger, director of the Institute for Astronomy at the University of Hawaii in Honolulu, and a member of the study team.
After subtracting the interspersed stars and galaxies the team found faint background glows in both the CIB and cosmic x-ray background (CXB). The results from the CIB and CXB studies revealed that the fluctuations in the backgrounds were consistent across the wavebands.
Spanning more than 5 years of data, the results were unexpected and may provide clues to the creation and evolution of the first galaxies in the Universe. "This is an exciting and surprising result that may provide a first look into the era of initial galaxy formation in the universe," said another contributor to the study, Harvey Moseley, a senior astrophysicist at Goddard. "It is essential that we continue this work and confirm it."
Results from this work were published in the May 20 issue of The Astrophysical Journal, as well as presented at the 222nd meeting of the American Astronomical Society meeting in Indianapolis earlier this week.