Black holes and quasars formed less than a billion years after the Big Bang

Supermassive black holes appear to exist at the center of every galaxy, dating back to some of the first galaxies in the universe. We have no idea how they got there. It should not be possible for them to grow from supernova remnants to enormous sizes as quickly as they do. We are not aware of any other mechanism that could form something large enough that exponential growth would not be necessary.

The apparent impossibility of supermassive black holes in the early universe was indeed a minor problem; The James Webb Space Telescope has made matters worse by finding previous examples of galaxies with supermassive black holes. In the latest example, researchers used Webb to characterize a quasar powered by a supermassive black hole, as it existed about 750 million years after the Big Bang. And it looks shockingly normal.

Looking back in time

Quasars are the brightest objects in the universe, actively fueled by supermassive black holes. The galaxy surrounding them provides them with enough material to form bright accretion disks and powerful jets, both of which emit copious amounts of radiation. They are often partially covered by dust, which glows as a result of absorbing some of the energy emitted by the black hole. These quasars emit so much radiation that they eventually push some nearby material out of the galaxy entirely.

So, the presence of these features in the early universe would tell us that supermassive black holes not only existed in the early universe, but were also incorporated into galaxies as they are more recently. But their studies were very difficult. For starters, we haven’t identified many of them; There are only nine quasars that date back to before when the universe was 800 million years old. Because of that distance, features are difficult to spot, and the redshift caused by the expansion of the universe takes the intense ultraviolet radiation from many elements and extends it into the deep infrared.

However, the Webb telescope was specifically designed to detect objects in the early universe through its sensitivity to the infrared wavelengths where this radiation appears. So the new research relies on pointing Webb towards the first of the nine quasars discovered, J1120+0641.

And it looks… remarkably normal. Or at least very similar to quasars from more recent periods in the universe’s history.

Mostly normal

The researchers analyzed the continuity of radiation from the quasar, and found clear indications that it was embedded in a mass of hot, dusty material, as seen in later quasars. This dust is a little hotter than some modern quasars, but this appears to be a common feature of these objects in the early stages of the universe’s history. Radiation from the accretion disk also appears in the emission spectrum.

Different methods for estimating mass produced values ​​for a black hole in the region of 10⁹ Many times the mass of the Sun, putting it clearly in the region of the supermassive black hole. There is also evidence, from a slight blue shift in some of the radiation, that the quasar is blowing material away at a speed of about 350 kilometers per second.

There are a few oddities. The first is that the material also appears to be falling inward at about 300 kilometers per second. This could be caused by material rotating away from us in the accretion disk. But if so, it must be met by material rotating toward us on the other side of the disk. This has been seen several other times in very early quasars, but the researchers acknowledge that “the physical origin of this effect is unknown.”

One option they suggest as an explanation is that the entire quasar is moving, jolted from its position at the galactic center by a previous merger with another supermassive black hole.

Another strange thing is that there is also an extremely fast flow of highly ionized carbon, moving twice as fast as in quasars at later times. We’ve seen this before, but there’s no explanation for it either.

How did this happen?

Despite the oddities, this object closely resembles recent quasars: “Our observations show that the complex structures of the dusty torus and the star [accretion disk] Can prove itself around a [supermassive black hole] “Less than 760 million after the Big Bang.”

Again, this is a bit of a problem because it suggests the presence of a supermassive black hole embedded in its host galaxy very early in the universe’s history. To reach the kind of sizes shown here, black holes push up against what’s called the Eddington limit, which is the amount of material they can pull in before the resulting radiation expels nearby material, suffocating the black hole’s food supply.

This suggests two options. The first is that these objects absorbed material well beyond the Eddington limit for most of their history, something we have not observed and certainly not true of this quasar. The other option is that they started huge (at about 10⁴ times the mass of the Sun) and continued to feed at a more reasonable rate. But we don’t really know how something this big could form.

Therefore, the early universe remains a somewhat confusing place.

Natural Astronomy, 2024. DOI: 10.1038/s41550-024-02273-0 (About digital IDs).