Black holes can eat a lot, but new research suggests they do so very neatly.
Researchers observed a high-energy X-ray black hole 22 million light-years away that swallows its "food" of gas and dust in a "surprisingly orderly fashion," a Gemini Observatory news release reported.
"It has elegant manners," research team member Stephen Justham, of the National Astronomical Observatories of China, Chinese Academy of Sciences, said. "We thought that when small black holes were pushed to these limits, they would not be able to maintain such refined ways of consuming matter, We expected them to display more complicated behavior when eating so quickly. Apparently we were wrong."
Larger black holes tend to produce softer X-rays while smaller black holes give off much harder emissions. The black hole the researchers observed, called M101 ULX-1, gives off soft X-rays; this is why researchers were surprised to discover the object was relatively small.
Models have shown soft X-rays come from the black hole's accretion disk and harder X-rays come from a "corona" around the disk.
"The models show that the corona's emission strength should increase as the rate of accretion gets closer to the theoretical limit of consumption. Interactions between the disk and corona are also expected to become more complex," the news release reported.
"Theories have been suggested which allow such low-mass black holes to eat this quickly and shine this brightly in X-rays. But those mechanisms leave signatures in the emitted X-ray spectrum, which this system does not display," lead author Jifeng Liu, of the National Astronomical Observatories of China, Chinese Academy of Sciences, said. "Somehow this black hole, with a mass only 20 [to] 30 times the mass of our Sun, is able to eat at a rate near to its theoretical maximum while remaining relatively placid. It's amazing. Theory now needs to somehow explain what's going on."