Researchers predict that the discovery of faint, vast galaxies has the potential to reshape our understanding of the universe and theories of galaxy formation. Using the most accurate and detailed cosmological simulations available, an international team of researchers has made an exciting prediction that could shed new light on our understanding of the universe: There are a vast number of dark galaxies waiting to be discovered in our cosmic neighborhood.
The study focused on ultradiffuse galaxies: dark galaxies with masses up to a billion suns - about one thousandth the mass of the Milky Way - spread over a region the size of the Milky Way. This makes them very dim and difficult to observe, so they remain poorly understood.
Researchers believe that the Local Group is a small galaxy cluster that currently contains about 60 known galaxies, including our Milky Way and the Andromeda Galaxy. Although only two ultradiffuse galaxies have been discovered in the Local Group so far, scientists believe that knowing the total number of ultradiffuse galaxies in the Local Group is crucial to our understanding of the universe.
So, how many other galaxies are lurking in our cosmic backyard? To find out, an international team of researchers conducted state-of-the-art simulation studies of our cosmic neighborhood. The HESTIA simulation, named after the ancient Greek goddess of domesticity, is the most accurate and detailed simulation of the Milky Way and its neighboring regions currently available. Simulations predict that there may be as many as 12 ultra-diffuse galaxies waiting to be discovered in the Local Group. Based on the analysis of the characteristics of ultra-diffuse galaxies in HESTIA simulations, the research team believes that several of these galaxies can be directly observed through existing survey data such as the Sloan Digital Sky Survey.
The discovery of these new galaxies could have profound implications for our understanding of galaxy formation and evolution. Current models suggest that up to half of the low-mass galaxies in the universe may be extended and diffuse galaxies, most of which are beyond our ability to observe with current technological capabilities. Since the number of galaxies in the universe is a strong prediction of various cosmological models, the size of the ultra-diffuse group of galaxies in the Local Group can be used to rule out the possibility of some of these models.
The study is published in the Astrophysical Journal Letters, titled "Undiscovered ultradiffuse galaxies in the Local Group": https://iopscience.iop.org/article/10.3847/2041-8213/acc2bb
Compiled source: ScitechDaily