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Is that the Force? Enormous laser beam shoots through a galaxy far, far away
The questions is really which side of the Force it belongs to.
Darth Vader would be jealous, but so would Luke Skywalker and Han Solo. Both the Rebels and the Imperial Forces only wish they had this laser (which could easily vaporize Luke’s X-wing, blast the Millennium Falcon or take down the Death Star) in their arsenal.
It might not be the Force, but it’s still a force, and a powerful one at that. Megamasers are monstrous radio-wave laser beams shot into space when galaxies collide. Now the most distant hydroxyl megamaser ever has been glimpsed 5 billion light years away through the MeerKAT telescope, one of the Square Kilometer Array (SKA) Pathfinder telescopes. It was also the first of its kind detected by MeerKAT. This hypersensitive telescope is just getting started.
Astronomer Marcin Glowacki, of Curtin University in Australia, led a study recently uploaded to the preprint server arXiv. The plasma in this laser is especially intriguing because it contains the star-forming gas entire galaxies are born from, and because it is so distant, we are seeing it as it was billions of years ago when older galaxies were just starting to emerge. What is in that plasma could tell us more about how galaxies evolved in the nascent universe.
“This is a hydroxyl (OH) megamaser, where hydroxyl molecules are made of one atom of hydrogen and one atom of oxygen,” Glowacki told SYFY WIRE. “When there are a lot of hydroxyl molecules, this emission cycle builds up quickly and causes a megamaser event.”
Megamasers shoot out from the dense gas that comes from a galactic merger. This is the first hydroxyl megamaser ever found, and hydroxyl molecules are created by that superdense gas. When one of these molecules absorbs light at a certain wavelength, it will spew out two photons, or particles of light, at the same wavelength, and the photons will inevitably end up being eaten by another hydroxyl molecule. That molecule will then emit two more photons, and the process will continue until there is so much emission buildup, it morphs into a megamaser.
Appropriately named ‘Nkalakatha,’ the Zulu word for “big boss,” this is a laser beam that the special effects in Star Wars wish they could be. It is 5 billion light years from Earth. Meaning, its light had to travel thousands of billions upon billions of miles through the void to reach us. No other telescope has seen a more distant megamaser before MeerKAT. After it watched the sky on the first night of the LADUMA (Looking At the Distant Universe with the MeerKAT Array) survey, Glowacki and his team detected the phenomena on the first night of a survey of those observations. Even such enormous eruptions are not always easily detected.
“One of the issues in detecting and observing megamasers has been manmade radio frequency interference (RFI) signals, which can make it difficult to see parts of space at the radio frequencies it affects,” he said. “Another challenge is radio telescope sensitivity.”
There are RFI signals being zapped all over. They come out of everything from your smartphone or radio to airplanes and satellites. Elon Musk’s Starlink satellite network is probably a nuisance. Depending on how faint or distant an object is, too many RFIs can be so intrusive that they block the radio signals it gives off. Radio telescopes that came before MeerKAT were also not as sensitive. If the technology had not been upgraded, it would have taken much longer to detect Nkalakatha, and only if it wasn’t blocked by an RFI onslaught.
MeerKAT can pick up on many signals that its predecessors might have missed because of its impressive 64-antenna array. LADUMA will involve over 3,000 hours of observations on just one narrow part of the sky. Mergers can reveal how a galaxy has grown through eons, which is why what is going on as they merge says something about their evolution. Galaxies that have just crashed into each other can be located through the megamasers they send into space.
“This amount of time using the excellent sensitivity of MeerKAT will allow us to detect both megamasers and star-forming neutral hydrogen gas to far greater distances than ever before, and allow us to study how galaxies evolve with time,” said Glowacki.
Because the merger that formed Nkalakatha occurred earlier than any other collision that formed a hydroxyl megamaser, comparing it to more recent phenomena can give an idea about galactic evolution going further back in time than ever before. Glowacki and his team plan to look deeper into the MeerKAT data on this one to find its faintest regions of hydroxyl emission. LADUMA is far from over, and MeerKAT might find itself peering at more distant megamasers.
Whichever side of the Force you’re on, too bad neither the Jedi nor the Sith could harness this king of lasers.