英语听力：自然百科 探索世界奥秘之Supermassive Black Holes(超大质量黑洞) Unit11（在线收听）

探索世界奥秘之Supermassive Black Holes(超大质量黑洞) Unit11

Those stars don't feel the black hole. They feel the rest of the stars in the galaxy. They don't know or care that the black hole is there. If you took the black hole away from the galaxy, they would be moving at exactly the same speeds.

This has led scientists to believe there couldn't possibly be any connection between the size of the black hole and the speed of the stars at the edge of the galaxy. They were about to be proved wrong.

As the two researchers went through the new data, they first had to calculate the mass of each black hole. Then they found out the speed at which the stars were moving at the edge of the galaxy and plotted all these figures on a graph.

As they came in, I will take that new black hole mass and the sigma for that galaxy and add it to my plot.

There should be no relationship between the two. Yet as they added each new point marking the speed of the stars against the mass of the black hole, a clear pattern started to emerge. To their amazement, the points lay in an obvious band across the graph. The properties were clearly related. The bigger the black hole, the faster the speed of the stars at the edge of the galaxy.

What we discovered is that the supermassive black holes at the center of galaxies and the galaxies themselves are really very tightly intertwined.

The stars at the edge of the galaxy have no physical connection with the black hole. Yet somehow their speed is tightly bound with the size of the black hole billions of miles away. If the two things aren't physically linked now, it means they must have been at some point in the past.

The fact that we see there is such a tight relationship between the speed of the stars and the black hole in the middle is a probe to what happened early on in the galaxy.

It screams at you something that you don't yet understand about the connection between galaxy formation and black hole formation.

The relationship points at an extraordinary idea: that galaxies and their giant black holes could be linked from birth. In fact, scientists thought that supermassive black holes might even be involved in the formation of galaxies themselves.