As a part of the SkyMapper project, an international team led by astronomers at The Australian National University (ANU) has found the fastest-growing black hole of the last nine billion years. This rapidly growing black hole is 500 times bigger than the black hole in our Galaxy. It has a mass of three billion suns.
The black hole gorges via a process called accretion, in which it siphons matter from a thin disk of gas and dust rotating around the massive object. This rapid accretion of matter resulted in a quasar blasting out enough energy to make it shines 7,000 times brighter than all the light from our Galaxy, with a visual magnitude of 14.5 – a measure of how bright an object appears to an observer on Earth. This quasar (designated SMSS J114447.77- 430859.3) is also the most luminous.
Lead researcher Dr. Christopher Onken and his co-authors describe it as a “huge, unexpected needle in the haystack.”
“Astronomers have been hunting for objects like this for more than 50 years. They have found thousands of fainter ones, but this astonishingly bright one had slipped through unnoticed.”
“Now we want to know why this one is different – did something catastrophic happen? Perhaps two big galaxies crashed into each other, funneling a lot of material onto the black hole to feed it.”
Co-author Associate Professor Christian Wolf said: “This black hole is such an outlier that while you should never say never, I don’t believe we will find another one like this.”
“We are fairly confident this record will not be broken. We have essentially run out of the sky where objects like this could be hiding.”
Co-author and ANU Ph.D. researcher Samuel Lai said, “It is 500 times bigger than the black hole in our Galaxy.”
“The orbits of the planets in our Solar System would all fit inside its event horizon – the black hole’s boundary from which nothing can escape.”
- Christopher A. Onken, Samuel Lai, et al. Discovery of the most luminous quasar of the last 9 Gyr. DOI: 10.48550/arXiv.2206.04204