[ad_1]
Scientists discovered a dwarf galaxy that shouldn’t exist by pure chance, according to a recent study.
The galaxy in question, PEARLSDG, was discovered by researchers at the University of Arizona using NASA’s James Webb Space Telescope in an attempt to conduct another study of galaxy clusters.
The results of this study were published in a peer-reviewed academic periodical. Astrophysics Journal Letter.
A dwarf galaxy far, far away: an accidental discovery
Dwarf galaxies, as their name suggests, are a type of galaxy in the universe that are relatively small. For comparison, a dwarf galaxy can contain as few as 1,000 stars, or it can contain billions of stars. But the Milky Way galaxy has about 200 billion stars. This means that dwarf galaxies can be difficult to spot because they are usually not very bright.
However, the number of dwarf galaxies is much greater than any other type of galaxy in the universe.
Typically, dwarf galaxies are either stationary, meaning they are near interacting larger galaxies, or isolated, meaning they exist alone and forming new stars. This understanding has been a pillar of scientific understanding of galaxy evolution.
However, these researchers were able to find stars that were not forming new stars or interacting with larger galaxies at all.
These scientists were studying the galaxy cluster as part of the James Webb Space Telescope Prime Reionization and Lensing Science for Extragalactic Regions (PEARLS) project, about 98 million light-years from Earth. The dwarf galaxy PEARLSDG was discovered completely by chance. It just appeared in some of the images they took.
But if this dwarf galaxy isn’t making new stars or interacting with larger galaxies, what’s going on?
Scientists believe that PEARLSDG may be just a rare example of an isolated stationary dwarf galaxy.
“These types of isolated stationary dwarf galaxies have never been observed before except in relatively few cases. Given our current understanding of galaxy evolution, they are in fact expected to exist. “Therefore, the fact that this object was seen helps improve theories about galaxy formation,” study leader Tim Carleton of the University of Arizona said in a statement.
“In general, dwarf galaxies that exist alone continue to form new stars.”
They were able to figure this out by imaging specific stars in this galaxy using instruments on the James Webb Space Telescope. This allowed scientists to determine that the star lacked certain color signatures found in newer stars.
In other words, not only is this galaxy not producing new stars, but all the stars in the galaxy are already very old.
But scientists don’t think this galaxy is a unique anomaly. Rather, they think it is probably one of many isolated quiescent dwarf galaxies waiting to be discovered. And the James Webb Space Telescope has proven that scientists have the tools to do just that.
Ultimately, this discovery raises further questions about the evolution of galaxies.
[ad_2]
Source link
