Supermassive Black Hole Have an Unexpected Appetite for Cold 'Meals'
A new study led by researchers from Yale University revealed a supermassive black hole feasting on clouds of cold, clumpy gas plunging to its gravitational pull.
Previously, astronomers believe that supermassive black holes in the largest galaxies got its energy from slow, steady diet of hot, ionized gas from the galaxy's halo in a process called accretion. However, a new study, published in the journal Nature, suggests that black holes may quickly devour clumps of gas clouds once in a while. This indicates that black holes usually dines on diffuse hot clouds but they may have some sort of "cheat" day when they consume fast moving clumps of cold gas.
"We can't know whether all or only part of this 'meal' of cold gas will ultimately fall into the black hole, but the ALMA data spectacularly highlights the importance of this kind of cold accretion," said C. Megan Urry, the Israel Munson Professor of Physics and Astronomy at Yale and co-author of the study, in a press release.
Their discovery comes as a surprise and was not planned. The original goal of their study is to get as sense of how many stars were being churned out at the Abell 2597 Cluster, a knot of about 50 galaxies spanning across some tens of thousands light years located one billion light years away from Earth.
For the study, the researchers analyzed data from the he Atacama Large Millimeter/submillimeter Array, or ALMA telescope in Chile to map out the locations and movement of cold gas. This cold gas has cooled and condensed out of the diffuse halo of hot gas surrounding a cluster, forming clumps. New stars are formed when this clump of cold gas collapses.
The researchers were the surprised two detect three cold gas clouds hurtling toward a black hole in a galaxy at the center of the cluster. Each gas clouds contained as much material as a million Suns, spanning tens of light years across and is plunging at million kilometers per hour.
"We got very lucky," claimed Michael McDonald, assistant professor of physics in MIT's Kavli Institute for Astrophysics and Space Research, in a statement.
"We could probably look at 100 galaxies like this and not see what we saw just by chance. Seeing three shadows at once is like discovering not just one exoplanet, but three in the first try. Nature was very kind in this case."
The team is now planning to use ALMA to search for similar "rainstorms" in other galaxies to determine if such cosmic weather is a common phenomenon.