Researchers suggest gas cloud could reveal black holes near center of Milky Way galaxy.

A team of researchers from Columbia University has published a paper in Physical Review Letters in which they suggest that the movement of gas cloud G2 near the center of our galaxy may reveal previously hidden small black holes. They note also that observation of G2's movement might lead to direct evidence of the existence of intermediate size black holes.

G2, a massive cloud of gasses three times the size of Pluto's orbit (but just 3 times the mass of Earth) was discovered moving through our galaxy two years ago by researchers at the Max Planck Institute. After noting its projected path, the researchers at Columbia have found that it will likely pass through a region of space that is thought to harbor as many as 20,000 small black holes (a single massive black hole is believed to exist at the center of our galaxy.) They suggest that researchers here on Earth might be able to actually see the interaction between the gas cloud and any black holes that are encountered. As the gas cloud comes near a black hole, they believe some of the gas will begin to spiral as it's pulled in by its gravity. That, they say, should cause a lot of heat to be expelled and x-ray light to be emitted—enough to be observable using x-ray telescopes. They go so far as to estimate that researchers might be able to see evidence of as many as 16 interactions.

More exciting to some in the field, is the possibility that the movement of G2 through our galaxy may give direct evidence of what are known as intermediate sized black holes—believed by some to be several times the mass of our sun. To date, their existence is purely theoretical. If G2 comes across one, and interacts with it, the event could prove that they really do exist. They, like the many small black holes in the universe, are believed to reside near the center of the galaxy, which is where G2 is heading. The researchers estimate it will reach the best position for study this September, giving researchers plenty of time to prepare.