Astronomers have found the farthest quasar ever seen, and like a handful of others found at this distance, it’s a big (literal) problem: the black hole that drives it is far too big for how long it’s been exist.
The quasar is named after its coordinates in the sky, J031343.84−180636.4 (let’s briefly call it J0313). This was found in a survey of the sky with Pan-STARRS, the Panoramic Survey Telescope and Rapid Response System, a relatively modest 1.8 meter telescope that nevertheless takes very deep pictures of the sky and examines the sky with different filters to get color information. on objects. Many distant quasars are usually bright in red, but emit very little light at blue wavelengths, making them easier to spot.
After J0313 was identified as a candidate, the much larger Magellan and Gemini telescopes took a spectrum that confirmed the great distance: the light we see from this object traveled more than 13 billion years to get here, which means we see it as it was about 670 million years after the big bang itself!
And that’s a problem. A quasar is an object we call a active galaxy. Every large galaxy has a supermassive black hole at its core, and in some cases the black hole is actively fed, engulfing gas and dust and stars around it. This material forms a large flat disk around it, which becomes infernally hot. It glows so brightly that it can easily protrude from the stars in the rest of the galaxy!
To make matter more intense (again literally), the magnetic field in the disk winds in double vortices, like tornadoes, which pull matter away from the disk and blow it away just outside the black hole. If the beams are more or less pointed in our direction, it makes the galaxy even brighter. This is what makes the galaxy a quasar.
Given the brightness of J0313 and its distance, astronomers measure its total brightness – how much energy it emits – as 36 trillion times the Sun’s.
This is … clear. It’s almost three thousand times brighter than our own Milky Way. Oof.
So, what about the supermassive black hole that drives it all? In the case of J0313, the deep spectra of Magellan reveal the mass of the black hole. While the case revolves around the disk, some of the things are away from us, so that the light shifts to the red, and others to us, which shifts blue. The amount of color smear can be used to determine the mass of the black hole, and the number they get is crushing: 1.6 billion times the mass of the sun.
We know of many black holes with the mass, and some even larger. But it took billions of years to grow that big. The best in J0313 is 670 million years old, and in fact somewhat less. How did it get so big so fast?
This is an ongoing problem in cosmology. We’ve seen other quasars at about this distance, and they also have huge black holes in them, bigger than we think they can get in the short time (galactically speaking) they’ve had.
The problem is that black holes can eat material just as fast. Matter tends to form those disks around them, and the disk is so hot that the radiation it blows out hits the material that falls to the black hole and blows it away. For a given black hole, the rate at which it can eat is balanced by the radiation it emits, called the Eddington Limit. Eat too fast and it cuts off its own food supply.
This again means that it is very difficult to quickly get a black hole with more than a billion solar masses. However, there are different ideas on how to get around it. Perhaps smaller black holes (with thousands or hundreds of thousands of times the mass of the sun) form – seed black holes – that grow rapidly and merge into the budding galaxy. This can help a lot, although they still need to grow fast.
However, it is not entirely clear how this process works. We do not know of very many quasars at this distance (it is a large sky, there is not much so far, and it can be difficult to choose it from a busy area), but the fact that we of the see handful, they all have big black holes which means they grow somehow. I will notice that there are quasars with black holes with a lower mass and less powerful emission, but it is weaker and harder to find. And to find it would just point out that black holes can form with a lower mass, but that it’s still the problem of how the really monstrous people do.
The galaxy itself that surrounds the black hole apparently shines a few hundred times the stars that do the Milky Way, which it calls what we call. galaxy. It can be fastened with the mass of the black hole; a lot of material in it to make stars and feed a hungry animal in its core.
It is important to understand all of this. First, we know that galaxies and their black holes grow together, so to understand the one means to understand the other. But also through this we are informed about the circumstances when the universe was very young and still beginning. Moreover, the light of these distant objects passes next to objects closer to us on the way here, and how it affects that light tells us even more about the very not-so-distant Universe.
Now that we know it’s there, J0313 will be a primary target for many follow-up observations to learn more about it. These quasars are a big problem, and the more we know about them, the greater the chance that we will find the solution.