Tuesday, March 28

Hubble’s latest discovery: a black hole that creates stars instead of gobbling them

With more than three decades behind him – quite a lot, in the case of a telescope that went into space with a useful life expectancy of 15 years— and its successor already on the way, Hubble continues to bring us joy. And also valuable lessons about the universe. The last one has to do with black holes and the image that we usually have of them as “hungry” astronomical objects endowed with a voracious appetite and an enormous destructive force.

In its latest investigation, Hubble has located one in the heart of Still 2-10 —a dwarf galaxy 30 million light-years away with a tenth of the stars in the Milky Way—which stands out for just the opposite: his role as a “star maker”.

The observations achieved thanks to Hubble have allowed a team of researchers led by Amy Reines, from Montana State University, verify that —instead of swallowing them— the black hole located in the center of Henize 2-10 has contributed to the formation of stars. Specifically, the telescope has given them a clear picture of the connection between the black hole and a neighboring star-forming region which is about 230 light years away.

A gigantic “umbilical cord”

“Henize 2-10 is close enough that Hubble could capture both the images and spectroscopic evidence of a black hole outflow very clearly. The additional surprise was that instead of suppressing star formation, the outflow was triggering the birth of new stars”, says Zachary Schutte, a Reines graduate student and author of the study, who just posted on Nature.

The US space agency compares that “connection” between the black hole and the star-forming region with a gas flow that extends through space like “an umbilical cord to a brilliant stellar nursery”. Spectroscopy shows that this powerful “jet” from the black hole hits a dense cluster of pre-existing gas.

“Hubble data on the speed of the black hole outflow, as well as the age of young stars, indicate a causal relationship between the twoyes A few million years ago, hot outflowing gas crashed into the dense cloud of a stellar nursery and spread out. Now the young star clusters are aligned perpendicular to the outflow, revealing the path of their propagation.” clarifies NASA, which underlines how the black hole is apparently contributing to the burst of new star formation taking place in the galaxy.

The key would be the size of the Henize black hole 2-10. Although these astronomical objects exert a brutal gravitational pull, material falling towards them can sometimes end up redirected by magnetic fields into gas streams and jets.

In the case of the largest supermassive black holes in the center of the galaxy, these “outflows” are too fast to allow star formation, but in Henize 2-10, its smaller size allows its to be larger as well. slow. Result: It compressed the accumulation of gas enough to favor the generation of stars. According to NASA in a statement, the outflow moved to about 1.6 million kilometers per hour.

Hubble Blkhole Henize2 10 Inset

Experts estimate that the Henize 2-10 hole has one million solar masses, quite far from the largest galaxies, which can host black holes with more than a billion times the mass of our Sun. For Reines, these types of objects can be crucial to help us in a complex task: solving the mystery of how supermassive black holes formed in the early universe. “It is a persistent puzzle for astronomers. The relationship between the mass of the galaxy and its black hole can give clues”, details the US agency.

Experts now have several theories about the origin of supermassive black holes, hypotheses that focus on the implosion of stars, the special conditions of the early universe or dense star clusters. Having maintained a reduced dimension, astronomers believe dwarf galaxies like Henize 2-10 can be of great help: their black holes would serve as “analogues” of those in the early universewhen they began to form.

“The era of the first black holes is not something that we have been able to see, so it really has become the big question: where do they come from? Dwarf galaxies may retain some memory of the propitious black hole scenario that has otherwise been lost to time and space,” Reines muses. in statements collected by NASA.

Black Holes: Simple Answers to Some of the Big Questions Raised by the Most Mysterious Objects in the Universe

For now, the latest Hubble observations help us to better understand Henize 2-10 itself and settle the debate about the origin of its radiation. Some astronomers have suggested that its origin could be in a supernova remnant, but the pattern that the telescope has just shown is irrefutable proof for researchers that it is a black hole.

Images | NASA