The Hubble Telescope has been orbiting Earth for more than thirty years.
Nationalgeographic.co.id—Recently observations using Hubble telescope surprising scientists who are studying galaxy–galaxy beginning in the universe. Early in 2021 they found six galaxy large bodies that appear to have died during the most active period of star birth in the universe.
“At this point in our universe, everyone galaxy should form a lot of stars. This is the peak age of star formation,” Kate Whitaker, an assistant professor of astronomy at the University of Massachusetts and lead author of a recent study on six galaxy such, in a press release shared by NASA.
Without the cold hydrogen gas needed to fuel the stars and give birth to new stars, the galaxies essentially die. The galaxies also cannot rejuvenate themselves, even if they have absorbed small galaxies and gas clouds near them.
Image Processing: Joseph DePasquale (STScI)
The galaxies that died mysteriously.
But the reason why the galaxies died in the first place they died remains a mystery.
“Is a supermassive black hole at the center of the galaxy igniting and heating all the gas?” said Whitaker proposing a hypothesis.
“Then the gas might still be there, but it’s hot now. Or it could be that the gas was ejected and is now prevented from collecting back into the galaxy. Or has the galaxy used up all its gas, and the supply is cut off?”
“These are some open questions that we will continue to explore with new observations in the future,” added Whitaker.
Hubble is used by astronomers to detect galaxies. Then, using the Atacama Large Millimeter/submillimeter Array (ALMA) in northern Chile, the researchers were able to detect whether the galaxies contained cold dust that signaled the presence of hydrogen gas.
But because the galaxies are so old and so far away, scientists wouldn’t be able to find them without a technique known as “gravitational lensing,” NASA explains.
The research team used supermassive galaxy clusters closer to Earth as natural telescopes. The light from these distant objects is then magnified by the gravity of this supermassive galaxy cluster.
Full view of the Milky Way galaxy. There’s still a lot we don’t know about the contents of our galaxy.
According to NASA, when these very distant galaxies are behind this supermassive galaxy cluster, they appear stretched and enlarged in the image, which helps astronomers see details that would otherwise be lost without magnification of the galaxy cluster.
“Using strong gravitational lensing as a natural telescope, we were able to find the most distant, most massive, and first galaxies to stop star formation,” said Whitaker.
“I like to think of it like doing science in the 2030s or 40s—with powerful next-generation space telescopes—but today by combining the capabilities of Hubble and ALMA, driven by powerful lensing.”
Mohammad Akhshik, principal investigator of the Hubble observation program, said his team had collected the largest sample to date of rare dead galaxies in the early universe. His team is called REQUIEM which stands for Resolve QUIEscent Magnified Galaxies At High Redshift.
“REQUIEM collected the largest sample to date of rare, strong-laced, and dead galaxies in the early universe, and a strong lens is the key here,” said Mohammad Akhshik.
“This lensing amplifies light at all wavelengths making it easier to detect, and you also get higher spatial resolution when you have these galaxies spanning the sky. You can basically see the interior of those galaxies on a physical scale that it’s much more subtle to figure out what’s going on there.”