Researchers gained insight into how the mass of a galaxy is related to the mass of its black hole.
A team of scientists looked at "football-shaped" groups of stars called elliptical galaxies, and found mysterious dark matter appears to influence black hole growth, Harvard University reported.
"There seems to be a mysterious link between the amount of dark matter a galaxy holds and the size of its central black hole, even though the two operate on vastly different scales," said lead author Akos Bogdan of the Harvard-Smithsonian Center for Astrophysics (CfA).
Past observations have found a relationship between the mass of a central black hole in the stars in elliptical galaxies, but new findings have also discovered a link between black hole mass and a galaxy's dark matter "halo." In this recent study the researchers set out to determine which relationship was more significant.
Dark matter is heavier than normal matter by a factor of six to one. We have never directly observed dark matter but believe it exists because of its gravitational effects and the way it appears to hold together galaxy clusters. Scientists believe every galaxy is surrounded be a halo of dark matter that can weigh as much as a trillion suns.
To investigate this puzzling relationship the researchers studied more than 3,000 elliptical galaxies, using the observations of star movements to determine the weight of both the galaxies and the black holes they contained. X-ray measurements of hot gas around the galaxies allowed the scientists to measure the weight of the dark matter halos.
The team determined there was a "distinct relationship" between the mass of the dark matter halo and the black hole mass. This phenomenon is most likely based on the way elliptical galaxies form. These types of galaxies are born when smaller galaxies merge together, allowing the heavy outer dark matter to mold their shape and guide the growth of the black holes.
"In effect, the act of merging creates a gravitational blueprint that the galaxy, the stars and the black hole will follow in order to build themselves," Bogdan said.
The findings were published in a recent edition of the Astrophysical Journal.
