How Gluttonous Young Black Holes Chowed Down in the Early Universe
At the ends of the universe are massive black holes and now, scientists have found out a little bit more about them. A new model reveals how early black holes could have grown to masses over a billion times that of our own sun.
Normally, a black hole forms when a massive star explodes after all of its nuclear fuel is spent. Without the fuel at its core pushing against gravity, the star collapses and while much of the material is flung outward in a supernova blast, some of the material falls inward and forms a black hole. These black holes are usually only about 10 solar masses.
Ancient quasars, though, seem to be the exception to the rule. These giant bodies feed on interstellar gas and swallow large quantities non-stop. Scientists can spot these quasars at the edges of the universe. Since they were first discovered, scientists have wondered what process could lead to a small black hole to gorge and fatten to such an extent so soon after the Big Bang.
That's why the scientists created their model of a black hole in the very early universe. At that time, gas streams were cold, dense and contained much larger amounts of material than the thin gas stream in today's universe-which explains the larger black holes. The new black holes moved around, changing direction as it was knocked by other baby stars in its vicinity. As it moved, it swept up more and more gas into its orbit-so fast that the gas couldn't settle into a slow, spiraling motion. After a mere 10 million years, the black hold would have grown to be about 10,000 solar masses.
The model reveals how the black holes eventually managed to grow to be millions of solar masses. By sucking in this gas at a more rapid rate than in our modern universe, these black holes grew to immense sizes. This tells scientists a bit more about the evolution of black holes and a bit more about the early origins of our universe.
The findings are published in the journal Science.