英语听力:自然百科 探索世界奥秘之Supermassive Black Holes(超大质量黑洞) Unit06(在线收听) |
探索世界奥秘之Supermassive Black Holes(超大质量黑洞) Unit06 When the results came down from the telescope he saw something that was completely unexpected. The picture from the active galaxy where he hoped to find a black hole was unreadable. NGC 1068 was just too far away for the telescope to get a clear picture. The surprise came from Andromeda, the quiet, normal galaxy right next to us. I was astonished when I found what I was looking for, but not where I was looking for it. This jog in this dark band shows that on one side the stars are moving very rapidly away from us at 150 kilometers a second which is 500,000 kilometers an hour. Dressler thought there could only be one thing that would cause the stars to move this fast: a supermassive black hole and he wasn't alone. Fellow Nuker John Kormendy had found exactly the same thing. The moment I could see that wiggle, so I knew essentially instantly that there was a very good chance this would be a supermassive black hole. When you see something like that, you know you are on to something. They'd found evidence of the most terrifying force in nature. But worryingly it wasn't in some far-off active galaxy. This supermassive black hole was in the very ordinary galaxy right next door to us. Andromeda seemed to have a black hole but no bright quasar. If there was a supermassive black hole, why wasn't it shining? That suggested that there was not stuff falling in. Maybe lots of galaxies could have a dormant phase where they had a supermassive black hole but they weren't being fed so they weren't shining. A few theorists had predicted this very thing: supermassive black holes could exist in two states. wiggle: move with short movements up and down or from side to side. be on to something: have an idea that is likely to lead to an important discovery dormant: temporarily inactive |
原文地址:http://www.tingroom.com/lesson/zrbaike/2008/498772.html |