To look back at the early years of the Universe, scientists must formulate many hypotheses. But sometimes we have better instruments that then allow them to confirm or replace those assumptions.
This happened recently during our study of J0529, a supermassive black hole that is currently the brightest known quasar in the Universe.
A new paper from a large team of researchers used the GRAVITY+ instrument on the European Southern Observatory’s (ESO) Very Large Telescope (VLT) interferometer to map the wide region of this unique object (BLR), and thus calculated a new updated mass, 10 times smaller than previous estimates.
Related: Scientists Find Giant Black Hole Growing 2.4 Times Faster Than Theoretical Limit
To put things in perspective, this mass is still 800 million times the mass of our Sun. But why such a gap between the initial estimate of 10 billion solar masses and the new one?
Better technology, in this case the VLT interferometer, has disproved a common hypothesis made by the original research team that discovered J0529, and which has larger implications for our understanding of the size of black holes, particularly in the early Universe.
Previously, a standard method for calculating the mass of a black hole was to approximate it by taking the square of the orbital velocity of the accretion disk surrounding the black hole and multiplying it by the distance to the black hole.
When J0529 was discovered in 2024, researchers knew the distance – about 12.5 billion light years away, when the Universe itself was only 1.5 billion years old. And they thought they could measure the orbital speed of the accretion disk by measuring the width of its emission lines.
Emission lines are the spectral signal from light emitted by superheated gas and dust in the accretion disk.
The standard calculation of their orbital speed is based on the fundamental assumption that the “broader” the emission line, the faster the gas rotates. It would be large because it would reflect material moving both toward us (blue shift) and away from us (red shift).
The faster it goes, the more the lines are shifted, resulting in a “broader” profile in the data. Since J0529 had an extremely broad emission line, it was assumed that the gas must be moving quickly and therefore the supermassive black hole at its center must be extraordinarily large for the gas to be moving that quickly.
Using the GRAVITY+ instrument, which acts as an interferometer and significantly increases the VLT’s observing power by combining light from the four 8-meter telescopes into a single “virtual” telescope, researchers were able to directly view the broad region (BLR) around J0529 – the area of clouds orbiting the supermassive black hole.
In this image, they saw a huge jet of gas shooting out of the black hole at 10,000 km/s. This may seem counterintuitive, because black holes are commonly thought to absorb everything around them and nothing escapes.
frameborder=”0″allow=”accelerometer; autoplay; write to clipboard; encrypted media; gyroscope; picture in picture; web sharing” referrerpolicy=”strict-origin-when-cross-origin”allowfullscreen>
However, their gravitational pull can cause massive disturbances in the matter in the accretion disk, so that before the material can enter the black hole’s event horizon, it is ejected at astonishing speeds.
And because the speed at which the accretion disk rotates around the black hole is a main factor in calculating its mass, such jets can also distort measurements of the mass of their host black hole.
This is exactly what happened in the case of J0529. The 10,000 km/s jet significantly broadened the spectral lines that early researchers were studying, and they assumed that the extremely broad lines coming from J0529 were caused by extreme orbital velocities rather than outflows that had no bearing on the black hole’s mass.
frameborder=”0″allow=”accelerometer; autoplay; write to clipboard; encrypted media; gyroscope; picture in picture; web sharing” referrerpolicy=”strict-origin-when-cross-origin”allowfullscreen>
Once the flows were observed spatially, the researchers were able to subtract their value from the spectral lines and recalculate the mass of J0529, resulting in a mass that was only about 10% of the initial estimate. But again, for perspective, J0529 is still 800 million times the size of our Sun.
The study also provides additional evidence on some vexing problems in astrophysics, such as how supermassive black holes can grow billions of times the size of the Sun just a few hundred million years after the big bang.
J0529’s light jets are powered by a process called Super-Eddington Accretion, in which an object exceeds its “Eddington limit,” the maximum brightness at which an object can shine given its mass that will not carry away the material that makes it grow.
A black hole may exceed its Eddington limit for a while, but in doing so it will sacrifice some of its overall size in the long run, because materials that would otherwise contribute to its mass would be washed away by the pressure of its own light.
frameborder=”0″allow=”accelerometer; autoplay; write to clipboard; encrypted media; gyroscope; picture in picture; web sharing” referrerpolicy=”strict-origin-when-cross-origin”allowfullscreen>
The same jets blown in this way can have a major impact on galaxy formation, because they can stop star formation in their tracks and scatter material to other galaxies outside of the one that created the jet.
As we get more powerful telescopes, we will be able to get an even clearer picture of what is happening in these distant galaxies.
And I hope that these images will both allow us to test our hypotheses about what we know about the Universe, but also provide new insight into what we might discover there.
This is part of the reason why the cycle of technological progress enabling scientific discovery is so powerful.
This article was originally published by Universe Today. Read the original article.
