Dwarf galaxies are much smaller than the average sized galaxies, containing just a couple of billion stars. Our solar system is a part of the Milky Way Galaxy, which numbers between 200 and 400 billion stars. However, dwarf galaxies form the majority of the Universe’s galaxies. Scientists attempted to understand the relations between dwarf and larger galaxies in an international project. The dwarf galaxies movement around the larger ones offers important data about the structure of the Universe.
James Webb Space Telescope will be placed on Earth’s orbit in 2018 and is expected to contribute greatly to the understanding of distant processes. Primarily, JWST will attempt to find habitable planets outside the solar system.
Previously, dwarf galaxies were presumed to swarm around larger galaxies like bees. But new findings reveal that dwarf galaxies orbit less scattered than thought. Rather, these galaxies orbit in a larger coordinated movement around larger similar bodies. In 2013, scientists looked at Andromeda galaxy and found that about half of its dwarf galaxies revolve in a clearly defined plane with a 300.000 light years width. The plane has a one million light years diameter, clearly suggesting an organized movement.
Next, researchers attempted to understand more precisely how the galaxies interact, by using data from the Sloan Digital Sky Survey. The SDSS is performed with one optical 2.5 meters wide telescope at Apache Point Observatory, New Mexico, U.S. The red-shift survey offers a rich array of colored images and 3D maps covering about a third of the sky.
The dwarf galaxies movement resembles a dance
Lead author Neil Ibata said they “[w]e were surprised to find that a large proportion of pairs of satellite galaxies have oppositely directed velocities if they are situated on opposite sides of their giant galaxy hosts”. The researchers argue that because more than 50 percent of the analyzed galaxies display this choreographed movement, they might have discovered a universal law of movement for this celestial bodies.
Professor Geraint Lewis from University of Sydney’s School of Physics, one of the scientists from the international research project, stated that “[e]verywhere we looked we saw this strangely coherent coordinated motion of dwarf galaxies. From this we can extrapolate that these circular planes of dancing dwarfs are universal, seen in about 50 percent of galaxies,” said Professor Geraint Lewis. He added that “[t]his is a big problem that contradicts our standard cosmological models. It challenges our understanding of how the universe works including the nature of dark matter.” Dwarf galaxies movement have long preoccupied astronomers and the new discovery will have a deep impact over the field.