According to scientists from the Georgia Institute of Technology, they were able to find the reason for the recent (on space standards) in the Milky Way there was a real "megafeyerverk", in which the center of our galaxy is still in the process of star formation.
According to experts, the reason for this was a collision of several million years ago, a giant black hole in the center of the Milky Way with a black hole - the core of a small galaxy.
Make such inference allow unusual Fermi bubbles (district center of our galaxy), which are high-energy particles emissions, extending above and below the disk of the galaxy 30 000 light-years.
In addition, the center of our galaxy, there are three of the most massive clusters of young stars. These clusters are hundreds of young, hot stars, which burn only a few million years, just because of the fact that they are very hot. According to astronomers, this confirms that these stars were born recently (again on space standards). As for the old stars in the center of the Milky Way are very few.
Presumably, in the past, with the Milky Way ran a small satellite galaxy, which, according to the calculations of astronomers, about 13 billion years ago began to converge with our own, and to the extent that it approaches the interstellar gas and the stars themselves absorbed by the more massive of our galaxy. In this case, the black hole in this satellite galaxy, the mass of which is about 10,000 solar masses, continued its flight and about 10 million years ago, faced with a black hole in the center of the Milky Way.
Before this black hole was absorbed by a larger, it is a few million years at the center of our galaxy, which resulted in a massive loss of old stars and the formation of new, young.