Astronomers have found the farthest quasar seen so far and, like a handful of others found at this distance, have a huge problem (literally): the black hole that powers it is far too large for how long it has been around.
The quasar is named after its coordinates in the sky, J031343.84−180636.4 (let’s call it J0313 for short). It was found in a sky survey using Pan-STARRS, the Panoramic Survey Telescope and the Rapid Response System, a relatively modest 1.8-meter telescope that, however, takes very deep images of the sky, monitoring the sky using various filters for get color information. on objects. Very distant quails tend to be bright red, but emit very little light at blue wavelengths, making them a little easier to spot.
Once J0313 was identified as a candidate, the much larger Magellan and Gemini telescopes took on a spectrum confirming the immense distance: the light we see from this traveled object over 13 billion years let’s get here, that is, we see it as it happened about 670 million years after the Big Bang itself!
And that’s a problem. A quasar is an object we call active galaxy. Each large galaxy has a supermassive black hole in its core, and in some cases, the black hole actively feeds, devouring gas, dust, and stars around it. This material forms a huge flat disk around it, which heats up infernally. It shines so fiercely that it can easily surpass the stars in the rest of the combined galaxy!
To make the matter more intense (again, literally) the magnetic field in the disk rotates into twin vortices, such as tornadoes, which extract the matter from the disk and remove it right outside the black hole. If these beams are more or less pointed in our direction, they make the galaxy even brighter. That makes the galaxy a quasar.
Given the brightness of J0313 seen and its distance, astronomers measure its total brightness – how much energy it emits – as 36 trillion or of the Sun.
That’s … brilliant. Is almost three thousand times brighter than our own Milky Way. Oof.
So how about the supermassive black hole that fuels all this? In the case of J0313, the deep spectra taken by Magellan reveal the mass of the black hole. As matter revolves around the disk, some of the matter moves away from us so that its light moves to red and others to us, which turn blue. The amount of this stain of color can be used to determine the mass of the black hole, and the number they obtained is overwhelming: 1.6 billion times the mass of the Sun..
We know about a lot of black holes with that table and some even bigger ones. But they have had billions of years to grow to this size. At best, the one in J0313 is 670 million years old and, in reality, a little less. How did it grow so fast on such large proportions?
This is an ongoing problem in cosmology. I’ve seen other quasars at about this distance and they also have huge black holes, bigger than we think they can get in the short time (galactically speaking) they’ve been.
The problem is that black holes can eat the material so fast. Matter tends to form those disks around them, and the disk is so hot that the radiation it explodes hits the falling material into the black hole and blows it. For a given black hole, the rate at which it can eat is balanced by the radiation it emits, called Eddington Limit. Eat too fast and interrupt your own diet.
In turn, this means that it is very difficult to get a black hole with over a billion solar masses so fast. However, there are several ideas on how to get around this. Perhaps smaller black holes (thousands or hundreds of thousands of times the mass of the Sun) form – black seed holes – and they grow rapidly and merge into the nascent galaxy. This can help a lot, although it still has to grow very fast.
However, it is not clear how this process works. We don’t know many quasars at this distance (it’s a big sky, there aren’t many so far away and it can be difficult to choose them from a crowded area), but the fact that among the few we see, they all have huge black central holes means that they grow somewhat. I will notice that there may be quasars there with black holes with lower mass and less strong emissions, but they are weaker and harder to find. And finding them would only show that safe black holes can be formed, with a smaller mass, but the problem remains of how they do the truly monstrous ones.
The galaxy itself that surrounds the black hole apparently removes stars at a speed several hundred times faster than what the Milky Way does, thus becoming what we call galaxy starburst. This may be related to the mass of the black hole; much material in it to create stars and feed a hungry beast in its core.
It is important to understand all this. First, we know that galaxies and their black holes grow together, so understanding one means understanding the other. But this also informs us about the conditions in which the Universe was extremely young and still in its infancy. On top of that, the light of these distant objects passes by objects closer to us on the way here, and how they affect that light tells us even more about the not-so-distant Universe.
Now that we know it’s there, J0313 will be a prime target for a lot of later observations to find out more about it. These quasars are a big problem and the more we know about them, the more likely we are to find the solution.