This information will surely interest astronomical enthusiasts. As reported by our colleagues at Bigthink, astronomers at MIT (Massachusetts Institute of Technology) claim to have detected signs of galactic cannibalism. In fact, this term is used to refer to the process by which one larger sized galaxy swallows another smaller one.
The result is a more massive, often irregular, galaxy. The Milky Way itself is surrounded by dwarf galaxies that are believed to be the remains of galaxies that were born shortly after the universe was formed. One of these relics of primitive galaxies is Tucana II. It is an ultra-thin dwarf galaxy located more than 160,000 light years from our planet.
In a new scientific article published in Nature Astronomy, MIT PhD student Anirudh Chiti and colleagues report the discovery of strange phenomena in Tucana II. In particular, they claim to have discovered stars on the edge of the galaxy. Although these are far from the center of Tucana II, they still seem to be influenced by its attraction.
Based on this observation, astronomers concluded that the structure might contain a halo of dark matter. As our source points out, this finding also suggests that some of our knowledge of dwarf galaxies may be wrong, not least because the first galaxies in the universe were likely large and more massive than we think.
Colliding galaxies as seen from the Hubble Space Telescope. Photo credit: Wikipedia / Published by NASA, ESA, Hubble Heritage (STScI / AURA) -ESA / Hubble Collaboration, and A. Evans (University of Virginia, Charlottesville / NRAO / Stony Brook University), public domain
The result of one of the first galaxy mergers in the universe?
In addition, the team found that the stars on the outskirts of Tucana II are older than those near the center. And this is the first time that such a star imbalance has been observed. This unusual arrangement suggests that the primitive galaxy could be the result of one of the first galaxies in the universe, one much older than the other.
“We may see the first signature galactic cannibalism,” said Anna Frebel, professor of physics at MIT. Specifically, Tucana II may be the fruit of a galaxy that has devoured one of its smaller and more primitive neighbors. An event that would have sent a few stars to the periphery.
Further studies on the program
Tucana II is considered to be one of the oldest dwarf galaxies in the cosmos and will be further investigated in the future. MIT scientists believe, among other things, that it could contain other stars, even older ones. If so, his analysis could help understand the birth of the first galaxies in the universe. Note that Frebel and Chiti used data provided by the SkyMapper (Australia) and Magellan (Chile) telescopes as part of their research.