Possibly A Very Early Black Hole

robertmcgrath

Dec 29

Black holes are very mysterious. But one thing seemed very clear: black holes form when a star runs out of fuel and collapses. At least, this is what the basic textbooks and popular TV shows taught me.

However, in recent years this part of the story has become very problematic. Surveys have found very old, very large black holes, fully formed shortly after the big bang. There simply couldn't have been time for a star to form and die, and for the black hole to grow.

So, either the theories of the beginning of the universe are wrong, or the theories of black holes are wrong. Or both.

One possibility is that black holes can form from "seeds" besides a dying star. I gather that there are a dozen or more ideas about possible seeds, including the direct collapse of a really big cloud of gas.

This winter a team of researchers report the discovery of a really large black hole, tagged UHZ1, which is more than 14 billion light years away, and therefore formed when the universe was a mere 500million years old [2]. Their analysis indicates that this matches theoretical models of how an "over massive black hole galaxy" would form from direct collapse of gas.

If this finding holds up, it is the first confirmation of a black hold formed by something other than a dying star. This could clear up the mystery of early black holes: as Dennis Overbye suggests, "How many ways are there to leave this universe?" [3] Possibly, more than one.

This study used data from not one, but two NASA space telescopes [3]. The James Web ST measured the distance—using a nearer (3.5 light years) galaxy as a gravitational lens. The Chandra X-ray telescope was used to detect the characteristic radiation from the black hole.

Cool.

Lee Mohon, NASA Telescopes Discover Record-Breaking Black Hole, in NASA's Missions - Chandra, November 6, 2023. https://www.nasa.gov/missions/chandra/nasa-telescopes-discover-record-breaking-black-hole/
Priyamvada Natarajan, Fabio Pacucci, Angelo Ricarte, Akos Bogdan, Andy D. Goulding, and Nico Cappelluti, First Detection of an Over-Massive Black Hole Galaxy UHZ1: Evidence for Heavy Black Hole Seed Formation from Direct Collapse. arXiv arXiv:2308.02654, 2023. https://arxiv.org/abs/2308.02654
Dennis Overbye, How to Create a Black Hole Out of Thin Air, in New York times. 2023: New York. https://www.nytimes.com/2023/12/24/science/space/astronomy-black-holes.html