Astronomers have been suspecting strange ripples in hydrogen gas in the disk of our milky way since a long time. They believe that the cause of these strange ripples is the gravity of an unknown dwarf galaxy consisting of great amounts of dark matter. Scientists now claim that they might have discovered this so-called “Galaxy X”.
The prediction of an invisible dark matter dwarf galaxy orbiting our Milky Way, made in 2009, may have had its “observational confirmation,” say researchers at the Rochester Institute of Technology in New York.
RIT astronomer Sukanya Chakrabarti and her colleagues examined near-infrared data from by the European Southern Observatory’s VISTA telescope for discovering four young stars clustered in the constellation Norma.
“They can’t be part of our galaxy because the disk of the Milky Way terminates at 48,000 light years,” says Chakrabarti.
“These young stars are likely the signature of this predicted galaxy,” she says, suggesting the dwarf galaxy is difficult to see through the obscuring dust of our own galaxy and because the majority of its mass is invisible dark matter.
She was the first to predict that the dark matter actually exists in the year 2009 on the basis of her analysis of the ripples seen in our galaxy’s disc.
“I decided to see if I could actually find the thing,” she says. “It was a difficult prediction to test because it was close to the plane [of our Milky Way galaxy], and therefore difficult to see in the optical.”
The infrared ability of the VISTA telescope paved the way for Chakrabarti and her colleagues to peer into unexplored regions in the past that lie close to our galaxy’s disk plane and cannot be seen due to lack of light.
Dark method was just a theoretical concept but was never observed directly as a form of matter that would account for most of the matter and mass of our universe.
Huge galaxies such as our own milky way has a probability of consisting many small satellite galaxies dominated by dark matter and are hence difficult to see, according to the astronomers.
“The discovery of the Cepheid variables shows that our method of finding the location of dark-matter dominated dwarf galaxies works,” she says.
“It may help us ultimately understand what dark matter is made up of,” she adds.