The Brightest Quasar in the Universe Just Got a Major Upgrade
The universe is full of mysteries, and one of the most fascinating is the supermassive black hole known as J0529. This black hole, currently the brightest quasar in the universe, has been a subject of intense study for scientists. But a recent discovery has revealed a surprising twist in our understanding of black holes and their masses.
A team of researchers used the GRAVITY+ instrument on the European Southern Observatory's Very Large Telescope Interferometer to map the Broad Line Region (BLR) of J0529. This allowed them to calculate a new, updated mass that is 10 times smaller than previous estimates. This might seem like a small change, but it has big implications for our understanding of black hole sizes, especially early on in the universe.
The original estimate of J0529's mass was 10 billion solar masses, but the new calculation puts it at a more modest 800 million solar masses. This discrepancy highlights the importance of using better technology to make accurate measurements. In this case, the VLT's interferometer disproved a common assumption made by the original research team.
The standard way to calculate a black hole's mass is to approximate it by taking the square of the orbital velocity of the accretion disc surrounding the black hole and multiplying it by the distance to the black hole. However, this method relies on the assumption that a 'broader' emission line means the gas is moving faster. This assumption was challenged by the GRAVITY+ instrument's ability to directly observe the Broad Line Region (BLR) around J0529.
The researchers saw a massive jet of gas shooting away from the black hole at 10,000 km/s, which was initially thought to be caused by extreme orbital speeds. However, this jet was actually an outflow that had no bearing on the mass of the black hole. Once the outflows were spatially observed, the researchers were able to subtract their value from the spectral lines and recalculate the mass of J0529, resulting in a mass only about 10% of the original estimate.
This study also lends some additional evidence to some thorny problems in astrophysics, such as how supermassive black holes can grow to billions of times the size of the Sun only a few hundred million years after the big bang. The bright outflow jets of J0529 are being fed by a process called Super-Eddington Accretion, where an object exceeds its 'Eddington Limit', the maximum brightness at which an object can shine without blowing away the material that is causing it to grow.
As we get more powerful telescopes, we'll be able to get an even closer picture of what is happening in these far-away galaxies. And hopefully, those pictures will allow us to check our assumptions about what we know about the universe, but also provide new insight into what we might be able to find out there.
