The NYT news Tuesday that astrophysicists have discovered the oldest black hole yet, formed a mere 470 million years after the Big Bang, was shocking to say the least. The reason is that standard stellar evolution theory puts the emergence of black holes at the end of stellar life cycles (core collapse of > 2-4 solar mass stars) not near the Big Bang. And certainly not soon after it, in relative terms. See e.g.
But the findings, published Monday, confirm not only that regular black holes- but also supermassive black holes existed at the dawn of the universe. NASA's James Webb Space Telescope and Chandra X-Ray Observatory teamed up over the past year to make the observations, using the technique of gravitational lensing which I'd written about earlier, e.g.
Gravitational Lensing Exposes Further Discrepancy ...
Now think also about the cognitive dissonance that will be experienced by the cosmologists as well as your stellar astrophysicists: Given the universe is 13.7 billion years old, and that puts the age of this black hole at 13.2 billion years. Even more astounding to space scientists, this black hole is a whopper — 10 times bigger than the black hole in our own Milky Way. The galaxy is called UHZ1, and both the James Webb and Chandra space telescopes used gravitational lensing to magnify the region of space where UHZ1 and its black hole are located. The telescopes used the light from a much closer cluster of galaxies, a mere 3.2 billion light-years from Earth, to magnify UHZ1 and its black hole much farther in the background (See graphic in the link posted above about gravitational lensing).
UHZ1 is believed to weigh anywhere from 10 to 100 per cent the mass of all the stars in its galaxy, according to lead author Akos Bogdan of the Harvard-Smithsonian Center for Astrophysics, the work published in the journal Nature Astronomy. A companion article appeared in the Astrophysical Journal Letters.
To put it into perspective, that mass ratio is nowhere near the miniscule ratio of the (stellar) black holes in our Milky Way and other nearby galaxies — which come in at an estimated 0.1 per cent. According to Yale University's Priyamvada Natarajan, who took part in the study:
"It's just really early on in the universe to be such a behemoth. It's astounding how this thing actually is sitting in place already with its galaxy so early on in the universe."
The Chandra-Webb researchers believe the UHZ1 black hole formed from colossal clouds of gas that collapsed in a galaxy adjacent to one with stars. The two galaxies merged, and the black hole took over. The fact that Chandra detected it via X-ray confirms "without a doubt that it is a black hole," according to Natarajan. This is so given: "With X-rays, you're actually capturing the gas that is being gravitationally pulled into the black hole, sped up and it starts glowing in the X-rays."
Because it's 13.2 billion light
years away, the x-rays from vicinity of the black hole has taken 13.2 billion years to
reach NASA's telescopes, meaning that they're seeing light
emitted 13.2 billion years ago by an object that existed then.
The Webb telescope alone may
have spotted a black hole that is 29 million years older, according to
scientists, but it's yet to be observed in X-rays and verified. Researcher Natarajan
expects more early black holes will be found — perhaps not as far out, but
still quite distant - noting:
"We are expecting a new window to open in the universe, and I think this is the first crack. It's a pretty faint object, and thanks to like luck, nature has magnified it for us."
Launched in 2021 to a point one million miles (1.6 million kilometers) away, Webb is the biggest and most powerful astronomical observatory ever sent into space; it sees the universe in the infrared. The much older Chandra, which rocketed into orbit in 1999, has X-ray detection capabilities.
The import of this discovery is self-evident, in so far as its impact on theories of stellar evolution. But much more critical will be the dynamical and thermodynamical hypotheses-theories which follow - and which can be properly tested and confirmed. Right now, all we have are 'toss the darts at the wall' guesses which aren't good enough to even allow a self-consistent model.
Let's wait to see what further papers appear, especially in mainline journals like The Astrophysical Journal.
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