Scientists discover how the universe's first quasar formed
Credit: University of Portsmouth
The mystery of how the universe’s first quasars formed—something that has baffled scientists for nearly 20 years—has now been solved by a team of astrophysicists whose findings were published in Natural.
The existence of more than 200 quasars powered by supermassive black holes less than a billion years after the Big Bang remains one of the outstanding problems in astrophysics because it is never fully understood how they formed so early.
The expert team led by Dr. Daniel Whalen of the University of Portsmouth has discovered that the first quasars formed naturally in turbulent conditions from reservoirs of rare gas in the early universe.
Dr. Whalen, from the University’s Institute of Cosmology and Gravity, said: “This discovery is very exciting because it has reversed 20 years of thinking about the origin of the universe’s first supermassive black hole.
“We found a supermassive black hole at the center of today’s most massive galaxy, which could be millions or billions of times the mass of the sun. a cosmic lighthouse in the early universe—which existed less than a billion years after the Big Bang. And no one understands how they formed at such an early age.”
Several years ago, supercomputer simulations showed that early quasars could have formed at the junction of rare, cold, and powerful gas streams. Only a dozen of these exist in a volume of space a billion light years away, but a black hole must be 100,000 solar masses at birth. Today’s black holes form when massive stars run out of fuel and collapse, but are usually only 10-100 solar masses.
Astrophysicists have long theorized that 10,000–100,000 solar-mass stars formed in the early universe but only in well-tuned exotic environments such as a strong ultraviolet background or supersonic flows between gas and dark matter that bear no resemblance to turbulent clouds where the first quasar formed.
Dr. Whalen said: “We think these stars are a bit like dinosaurs on earth, they are very large and primitive. And they have a short lifespan, living only a quarter of a million years before collapsing into a black hole.
“Our supercomputer model goes back very early and finds that dense, cold gas streams capable of growing a billion solar-mass black holes in just a few hundred million years create their own supermassive stars without requiring unusual environments. The cold streams drive turbulence around them. the cloud that prevented normal stars from forming until the cloud became so massive that it collapsed simultaneously under its own weight, forming two giant primordial stars—one with a mass of 30,000 solar masses and the other with a mass of 40,000.
“As a result, the only primordial clouds that could form quasars just after the cosmic dawn – when the universe’s first stars formed – also easily created their own massive seeds. This simple and beautiful result not only explains the origin of the first quasars but as well as their demographics—their numbers in the early days.
“The first supermassive black holes were simply a natural consequence of the formation of structures in cold dark matter cosmology—children of the cosmic web.”
The paper “The Turbulent Origins of the First Quasar” was published in Natural.
Did black holes form immediately after the Big Bang?
Daniel Whalen, The turbulent cold stream gave birth to the first quasar, Natural (2022). DOI: 10.1038/s41586-022-04813-y. www.nature.com/articles/s41586-022-04813-y
Provided by University of Portsmouth
Quote: Scientists discover how the first quasars in the universe formed (2022, July 6) retrieved July 6, 2022 from https://phys.org/news/2022-07-scientists-quasars-universe.html
This document is subject to copyright. Apart from any fair dealing for purposes of personal study or research, no part may be reproduced without written permission. Content is provided for informational purposes only.
#Scientists #discover #universes #quasar #formed
Comments
Post a Comment