An article (link to the file in PDF format) published in the journal “Nature Astronomy” reports the identification of the brightest and most voracious quasar discovered so far, cataloged as J0529-4351. A team of researchers used various instruments to understand that it wasn’t a nearby star but a primordial quasar we see as it looked over 12 billion years ago.
The researchers estimated that the mass of the supermassive black hole that powers it is about 17 billion times the Sun’s, and it’s devouring materials around it at a very high rate, about the mass of the Sun every day. The study of this record-breaking primordial quasar can help reconstruct the history of the early universe and the processes that led to it becoming what it is today.
The top image (ESO/Digitized Sky Survey 2/Dark Energy Survey) shows the region of sky where quasar J0529-4351 is located. It was created from images forming part of the Digitized Sky Survey 2 while the inset shows the position of this quasar in the center in an image from the Dark Energy Survey.
Quasars are active galactic nuclei powered by supermassive black holes surrounded by large quantities of materials that are heated to the point of generating very strong electromagnetic emissions. It may seem strange that a quasar as bright as J0529-4351 wasn’t identified yet despite its distance. It was precisely that brightness that initially led to the suggestion that it be classified as a star. That’s because it fooled the automatic systems that analyze data collected by ESA’s Gaia space probe, a specialized space telescope whose mission is to map the sky.
Last year, the researchers who conducted the study of J0529-4351 corrected that tentative identification using observations conducted with the Australian National University (ANU) 2.3-meter diameter telescope at the Siding Spring Observatory, Australia.
Further analysis was possible using archive data from other instruments, and crucial information was obtained thanks to the X-Shooter spectrograph mounted on ESO’s Very Large Telescope (VLT) in Chile.
The examination of the data collected allowed to obtain the astonishing estimates of the characteristics of the quasar J0529-4351. The mass of the supermassive black hole that powers it was estimated at about 17 billion times the Sun’s. Its brightness is over 500 trillion times the Sun’s and is caused by a disk of materials that orbits the black hole that has a diameter of about seven light-years. The quasar is extremely active also when it comes to materials being devoured by the black hole, estimated to be about the mass of the Sun every day.
The characteristics of J0529-4351 make it the brightest and most voracious quasar discovered so far, a truly extreme example in a class of objects that is already extreme in its own right. The authors of its identification also wondered whether astronomers had missed the recognition of other, perhaps even more extreme, quasars.
Available instruments have improved enormously since astronomers discovered the first quasars but they can still be difficult to recognize. The GRAVITY+ instrument, an update of GRAVITY, an instrument mounted on the VLTI (the VLT interferometer), may allow further advances as well as the Extremely Large Telescope (ELT), now under construction.
While waiting for GRAVITY+ and ELT to enter service, this study also offers useful information to find other primordial quasars that could be under the astronomers’ noses without having been recognized. Having a larger sample of ancient supermassive black holes to study would help understand how they formed so soon after the birth of the universe and their influence on their host galaxies.
According to the authors of an article recently published in the journal “The Astrophysical Journal Letters”, the influence of those supermassive black holes on star formation in primordial galaxies could be much greater than previously thought. In essence, there are still parts of the history of the early universe that require further studies to be clarified to obtain a precise reconstruction.
