Dinner Time: Milky Way's Black Hole About to Consume a Cloud of Gas
Astronomers have their telescopes trained on a small gas cloud in the center of the Milky Way that's about to become the next meal of the supermassive black hole in the galaxy's core.
The doomed gas cloud, known as G2, is not the first to be consumed by black hole Sagittarius A* (or Sgr A*) but being able to observe the feast is a rarity, astronomers say.
Daryl Haggard, an astronomer at Northwestern University, is studying G2 carefully in order to help solve solve a long-standing cosmological mystery: Just how do black holes attain supermassive proportions.
Haggard, who used data from the Chandra X-ray Observatory and the Very Large Array to make her observations, reports that in just a matter of days the gas cloud will reach its closest approach to Sgr A*.
"Our most recent Chandra observation does not show enhanced emission in the X-rays," Haggard said in a statement. "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 said the observations of G2 will provide valuable insight into the growth and feeding of 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," she said. "Do they grow rapidly when they are young, like our kids do, or do they grow in fits and starts, whenever fuel becomes available? In watching the encounter between Sgr A* and G2 we may catch a massive black hole in the act of snatching its next meal," she said.
Haggard will present her observations at the upcoming meeting of the American Physical Society. She will show recent X-ray and radio wave data collected from the galactic core, including information on the largest flare ever seen from Sgr A*.
"Sgr A* and the newly discovered magnetic neutron star, SGR J1745-29, which appears to be in orbit around the black hole, are dishing out lots of interesting science," Haggard said. "We've detected the brightest X-ray flare yet observed from Sgr A* and gathered data that are causing us to overhaul of our understanding of the neutron star population in the galactic center."