–
Astronomers have discovered six galaxies around a supermassive black hole that existed when the Universe was less than a billion years old. It is the first time that such a close-knit group has been observed so soon after the Big Bang, the European Southern Observatory has told ESO.<!– –>
“This research was mainly driven by a desire to understand some of the most challenging astronomical objects: supermassive black holes in the early Universe,” said Marco Mignoli, astronomer at the National Institute of Astrophysics (INAF) in Bologna, Italy, and lead author of the research report.
Cobweb
Observations with ESA’s gigantic VLT telescope show several galaxies around a supermassive black hole that are located in a cosmic “spider web” of gas that extends over 300 times the size of the Milky Way. “The cosmic web filaments are like the threads of a spider web,” explains Mignoli. “The galaxies lie and grow where the filaments intersect and gas that feeds both the galaxies and the central supermassive black hole can flow through the filaments.”<!– –>
The light from this large web-like structure, with its black hole of one billion solar masses, has reached us from a time when the universe was only 900 million years old. “Our research has yielded an important piece of a still very incomplete puzzle: How could such extreme, yet relatively numerous, objects have formed and grown so soon after the Big Bang?” Said co-author Roberto Gill, also from INAF.
Fast growth
The very first black holes, believed to have formed in the collapse of the first stars, must have grown very quickly. Otherwise they would never have reached masses of a billion Suns within the first 900 million years of the universe’s existence. But astronomers grapple with the question of how these objects could collect so much gas in such a short time. The structure now discovered offers a likely explanation: The “spider web” and the galaxies within it contain enough gas to rapidly grow the central black hole into a supermassive colossus.
That of course raises the question of how those large web structures came about. Astronomers think giant dark matter halos are the answer. These vast regions of invisible matter are believed to have attracted enormous amounts of gas early in the history of the Universe. Together, the gas and invisible dark matter have formed web-like structures in which galaxies and black holes could develop.
The galaxies now discovered are among the faintest observable with current telescopes.
–
