13 billion light-years away, at the very edge of our observable universe, supermassive black holes lurk inside their galactic hosts, feeding. As the light took 13 billion years to reach us, these black holes actually evolved when the Universe was only a fraction of the age it is now — precisely 13.75 billion years old.
This new finding comes from the analysis of Chandra X-Ray Observatory data, where astronomers “stacked” images of 250 distant candidate galaxies as previously spotted by the Hubble Space Telescope. The stacking process allowed extremely faint X-ray emissions from the centers of the galaxies to multiply, highlighting the location of the black holes living in their cores, feeding off dust, gas and unfortunate stars.
This is a significant finding as black holes are known to reside inside local (young) galaxies like our own, but little was known about ancient galaxies.
“This finding tells us there is a symbiotic relationship between black holes and their galaxies that has existed since the dawn of time,” said research astronomer Kevin Schawinski of Yale University.
The team could only detect the most powerful X-rays emitted, however. This suggests these distant galactic cores are thick with dust, obscuring most of the black hole emissions from view.
The debate as to whether supermassive black holes formed before their host galaxies, or the black holes were formed as galaxies evolved, is still very much alive. However, in this case, we now know that supermassive black holes were present in the very early evolution of the earliest galaxies.
“These observations indicate that extremely massive black holes already existed as early as 700-800 million years after the Big Bang, which suggests that either they were born massive to start with, or they experienced rapid growth bursts,” said Priyamvada Natarajan, a cosmologist also at Yale. “Either scenario tells us much more than we previously knew, which is very exciting.”
More Chandra analysis of distant galaxies is now on the cards as astronomers gather a larger dataset in the hope of better understanding this cosmic “chicken or the egg” dilemma. Perhaps the chicken and the egg both came first.
Image: A composite image of NASA’s Chandra X-ray Observatory and Hubble Space Telescope (HST) observation — a combination of the deepest X-ray, optical and infrared views of the sky. Credit: X-ray: NASA/CXC/U.Hawaii/ E.Treister et al; Infrared: NASA/STScI/UC Santa Cruz/G.Illingworth et al; Optical: NASA/STScI/S.Beckwith et al.
Source: Yale University