How is it possible that there were such colossal black holes when the universe was just born? That’s a good question. Astronomers have long tried to understand how supermassive black holes might have formed in the early universe. They know that these cosmic titans would have needed to grow extremely fast to reach their supermassive state so quickly (approximately 1 billion years after the Big Bang). But it is not clear exactly where they found such huge amounts of matter to grow so large.
Now, new findings from the European Southern Observatory’s Very Large Telescope (VLT), published in the journal Astronomy & Astrophysics, may provide the answer.
Hidden in the deep centers of galaxies, huge black holes lurk in the shadows and feed on matter that dares to approach. Some go a step further, forming a network-like structure of galaxies, sucking gas from their captured prey to grow even more massively in size. What astronomers have detected is a one-of-a-kind event: six galaxies trapped in the web of a cosmic black widow, a monstrous black hole at a time when the universe was less than 1 billion years old.
Within a web-like structure of gas filaments is this group of galaxies that surround a supermassive black hole. The black hole itself is 1 billion times larger than the Sun and remember that they are so dense that not even light can escape its gravitational pull.
The six newly discovered galaxies reside within a vast network of gas, extending about 300 times the diameter of the Milky Way, and were identified thanks to extended observations by the VLT. After analyzing the data, the researchers determined that they were viewing these galaxies as they existed only 900 million years after the Big Bang, when the universe was just over 6% of its current age. This is the first time that we have found such a narrow grouping of galaxies at such an early stage in the universe.
This new finding will allow scientists to better understand how these cosmic beings evolve over time and grow in size.
Feeding a black hole
Scientists know that there is a limit to how fast a black hole can grow: the Eddington limit. But while this factor plays a key role in the formation of supermassive black holes in the early universe, the important thing here is to trace where they got their “food” from in the first place.
The key probably has to do with the vast cosmic web of the universe. This structure is woven through the entire cosmos, connecting distant galaxies, galaxy clusters, and superclusters of galaxies through threads of wispy gas known as filaments.
According to experts, this black hole and its surrounding galaxies probably fed on gas that was stored in a tangled knot of cosmic web filaments.
“The filaments of the cosmic web are like spider web threads,” explains Marco Mignoli, leader of the work. “Galaxies stay and grow where the filaments intersect, and the gas streams, available to power both the galaxies and the central supermassive black hole, can flow along the filaments.”
With the help of dark matter?
Referencia: M. Mignoli et al. Web of the giant: Spectroscopic confirmation of a large-scale structure around the z=6.31 quasar SDSS J1030+0524, Astronomy & Astrophysics (2020). DOI: 10.1051/0004-6361/202039045
