Black holes are the most massive objects in the universe. Their gravity is so strong that nothing can escape it – not even light. But according to a new NASA study, black holes may play a more complex role in galactic ‘ecosystems’. In particular, a black hole has been found to contribute to the formation of a new star in its vicinity, providing startling clues to how massive black holes evolved in the first place.
An excellent incubator
About ten years ago, Amy Reines, then a graduate student, discovered a black hole in the galaxy about 30 million light-years from Earth, in the southern constellation Pyxis. She knew something was wrong right away, but it had to be nearer new Hubble observations clarify the situation.
“Just 30 million light-years away, Henize 2-10 is close enough that Hubble was able to capture both the image and the spectral evidence of the black hole’s outflow very clearly. What’s even more surprising is that, instead of stopping star formation, outflows trigger the birth of new stars,” said Zachary Schutte, Reines PhD student and lead author of the new study. .
The galaxy, known as Henize 2-10, is a so-called “starburst” galaxy – a galaxy where stars are forming at a much higher rate than normal, about 1,000 times faster. Galaxies are also relatively small – so-called dwarf galaxies – and have black hole at its center, like the Milky Way.
The researchers were aware of an unusual cocoon of gas in the region, but Hubble also managed to image an outflow associated with the central black hole. Although this process is still not fully understood, astronomers believe that black holes (or at least some black holes) have an outflow despite their great gravity. During Henize 2-10, this outflow, traveling at about a million miles per hour, crashed into the cocoon – and as it turned, the newborn stars followed the flow’s path.
In large galaxies, the opposite happens: matter falls towards the black hole forming jets of plasma that do not allow the formation of stars. But it seems that, in the less massive Henize 2-10, the outflow has the right characteristics to precipitate new star formation. In the past, studies have mainly focused on larger galaxy, where there is more observational evidence. Dwarf galaxies are still understudied, and only thanks to Hubble have researchers been able to study this.
“Hubble’s amazing resolution clearly reveals a corkscrew-like pattern in the velocity of the gas, which we were able to fit into the model of an outflow from a moving black hole or oscillate. The supernova remnant won’t have that pattern, and so it’s good evidence for our smoke gun that this is a black hole,” said Reines.
The role of black holes in the universe is one of the biggest puzzles in astronomy, and the more data there are, the more it starts to seem like it’s not a simple role but a complex one. complex. For example, it was recently shown that researchers realized that most (if not all) galaxies have black holes at their center. The larger the galaxy, the larger the central black hole – or possibly, vice versa, and the mass of the black hole affecting the galaxy.
But we don’t really know how these central black holes (often called supermassive black holes) form. Some researchers suspect that they form like “regular” black holes and are somehow accumulating more and more massive; others believe that they can only form under special conditions in the early universe; A further competing theory claims that the “seeds” of these black holes come from dense star clusters collapsing under gravity. The black hole at Henize 2-10 may provide clues to these theories.
Black holes in galaxies remain relatively small in cosmic time and do not accumulate much matter. This suggests that it has been relatively unchanged since its formation, essentially providing a window into the early days of the universe.
“The era of the first black holes is not something that we can see, so it has really become a big question: where did they come from? Dwarf galaxies may retain some memory of the black hole seeding scenario that has been lost into time and space,” concluded Reines.
https://www.zmescience.com/space/hubble-spots-black-hole-giving-birth-to-new-star/ How did Hubble discover a new “born” black hole?