cnn翻译6月19-5

Why is it significant?It✀s unclear which came first: the galaxy or the black hole, Schawinski said. The Chandra observations indicate that proto-galaxies already had central black holes, but it seems that the black holes and their galaxies are growing together.We see that pattern in more modern star systems: The bigger the black hole, the larger the galaxy around it. The Milky Way has a black hole in its center, too, about 4 million times the mass of the sun. "All the black holes we see at the centers of galaxies today are in a way descended from those baby black holes we see at the dawn of the universe," he said. How that happens is still a mystery, but this discovery shows that this symbiotic relationship went back to the dawn of the universe, Schawinski said.It could also change the way we think about the history of our universe, Melia said.If the black holes did come first, they would have played a critical role in the formation of the overall structure of the universe, Melia said. A young galaxy, shown in this artist✀s impression, has dust and gas at its center hiding a black hole."In some strange, indirect way, we may owe our existence to these black holes, because many of the galaxies may not have formed at all if it weren✀t for the black holes being there first," said Melia, who was not involved in the study. These observations of early black holes also shed light on how the universe became transparent. The very early universe was full of atomic hydrogen, a period called the "dark ages" because it was completely opaque, Schawinski said. Some mysterious event "re-ionized," or turned the hydrogen into charged particles called ions, such that light could travel freely.The Nature study suggests that a typical black hole could not have "lit up" the universe in this way. That✀s because ultraviolet light would have been trapped behind gas and dust; only the highest-energy X-rays could escape, and they do not have this ionizing property.What✀s next?Schawinski✀s group plans to push even further into the early universe to gain more insights into the early black holes. But clues may also emerge at the Large Hadron Collider, the $10 billion particle smasher here on Earth at the European Organization for Nuclear Research (CERN). Insights from the LHC experiments might yield new properties of physics that could potentially explain the mysterious formation of the universe✀s earliest black holes, Melia said.