Astronomers say they're getting a rare opportunity to observe the feeding habits of a black hole, as the supermassive example in the center of our own Milky Way galaxy is about to consume a cloud of dust and gas.
Northwestern University researcher Daryl Haggard has watched as a gas cloud dubbed G2 is edging closer to a black hole astronomers have named Sgr A*, hoping to answer a significant question, namely how black holes attain their supermassive proportions.
Haggard has made use of two renowned observatories, the Very Large Array near Socorro, New Mexico, and the orbiting Chandra X-ray Observatory, to collect data on an encounter she hopes could provide a spectacular cosmic show.
It could happen any day, she says, but there are signs we may have to wait a bit yet.
"Our most recent Chandra observation does not show enhanced emission in the X-rays," Haggard says. "From the X-ray perspective, the gas cloud is late to the party, but it remains to be seen whether G2 is fashionably late or a no show."
Haggard, a postdoctoral researcher at the Center for Interdisciplinary Exploration and Research in Astrophysics at Northwestern, says she hopes the observations can reveal secrets of the feeding and growth of the universe's supermassive black holes.
"We know they are big, and we know they are out there -- in vast numbers -- but we aren't sure in detail how they get their mass."
The encounter of G2 and Sgr A* will provide an opportunity to watch a black hole in the very act of consuming its next meal, she says, which could help explain the processes by which they grow.
"Do they grow rapidly when they are young, like our kids do, or do they grow in fits and starts, whenever fuel becomes available?" she asks.
Astronomers now generally accept the assumption that most elliptical galaxies and spiral galaxies such as our Milky Way have supermassive black holes at their centers.
Sgr A* was discovered in 1974 by instruments at the National Radio Astronomy Observatory in Charlottesville, Va., and has been the subject of intense scientific observation and study ever since.
