Astronomers predict that large spiral galaxies, like our Milky Way, have hundreds of satellite galaxies orbiting around them. While a few satellites are visible, like the Magellanic Clouds, many other galaxies are too dim to see. Scientists suspect that these faint satellite galaxies are primarily comprised of mysterious "dark matter," which makes up 85 percent of all matter in the universe and so far remains undetected.
Using supercomputers at the National Energy Research Scientific Computing Center (NERSC), Sukanya Chakrabarti, an assistant professor of physics at Florida Atlantic University, developed a mathematical method to uncover these "dark" satellites. When she applied this method to our own Milky Way galaxy, Chakrabarti discovered a faint satellite might be lurking on the opposite side of the galaxy from Earth, approximately 300,000 light-years from the galactic center.
According to Chakrabarti, the dark satellite galaxies create disturbances in the cold atomic hydrogen gas at the edges of the spiral galaxy's disk, and these perturbations reveal the mass, distance and location of the satellite. With the help of NERSC systems, she successfully validated her method by analyzing the radio observations of the Whirlpool Galaxy, which has a visible satellite one-third of its size, and NGC 1512, which has a satellite one-hundredth its size. Her calculations correctly predicted the mass and location of both of the known satellite galaxies. [ Ссылка ]
