It’s a well-known fact that supermassive black holes (SMBH) play a vital role in the evolution of galaxies.
Their powerful gravity and the way it accelerates matter in it’s vicinity causes so much radiation to be released from the core region – aka. an active galactic nucleus (AGN) – that it will periodically outshine all the stars in the disk combined.
In addition, some smbhs accelerate infalling dust and gas into jets that emanate from the poles, sending streams of super-heated material millions of light-years at close to the speed of light.
Since the frist of these “relativistic jets” was observed, scientists have been eager to learn more about them and their role in galaxy evolution. In a surprising first, a team of astronomers led by researchers at the University of California, Irvine (UC Irvine) and the Caltech Infrared Processing and Analysis Center (IPAC) recently uncovered the largest and most extended jet ever observed in a nearby galaxy.
Their observations also revealed vast “wobbly” structures, the clearest evidence to date that SMBHs can dramatically reshape their host galaxies far beyond their cores.
Their findings, published in the journal Karl G.Jansky Very Large Array (VLA). While Webb’s infrared data revealed the energetic heart of the galaxy, Keck’s optical data showed how that energy propagates outward.The VLA radio data, meanwhile, revealed a pair of plasma jets twisted into a helical pattern as thay move outward. The combined data presented a compelling picture, with a few surprises along the way.
For instance, the Webb data identified intensely energized “coronal” gas, the superheated plasma erupting from either side of the black hole, measuring several thousand parsecs across. Most observed coronae measure in the hundreds of parsecs, making this the most extended coronal gas structure ever observed. Meanwhile, the VLA radio data revealed a pair of plasma jets twisted into a helical pattern as they moved outward, evidence of a rare phenomenon in which a jet’s direction slowly wobbles over time (known as jet precession).
In addition, the KCWI data showed that the jet arrests star formation by stripping the galaxy of gas at a rate of about 20 Solar masses a year. But what was most surprising was the fact that these jets were observed in a relatively young galaxy like VV340a, which is still in the early stages of a galactic merger. typically, such jets are observed in older elliptical galaxies that have long since ceased star formation.This discovery challenges established theories of how galaxies and their SMBHs co-evolve and could provide new insights into how the milky Way came to be. Said Kader:
This is the first time we’ve seen a precessing, kiloparsec-scale radio jet driving such a massive outflow in a disk galaxy.There’s no clear fossil record of something like this happening in our galaxy, but this discovery suggests we can’t rule it out. It changes the way we think about the galaxy we live in.
The next step for the team will involve higher-resolution radio observations to determine whether a second SMBH could be at the center of VV340a, which could be causing the jets’ wobble. “We’re only beginning to understand how common this kind of activity may be,” said Vivian U, an associate scientist at Caltech/IPAC and the second and senior author of the study. “With keck Observatory and these other powerful observatories working together, we’re opening a new window into how galaxies change over time.”
The original version of this article was published on Universe Today.
