| The most energetic particles in the universe likely come from enormous black holes nestled in the restless hearts of traumatized galaxies, scientists say. |
科学家们称，宇宙中能量最高的粒子很可能来自巨型黑洞，这些黑洞坐落于备受创伤星系的动荡核心区域。 |
| Where these cosmic "bullets" originated has been a source of much speculation, with scientists proposing everything from gamma ray bursts to decaying dark matter. |
这些宇宙“子弹”（指能量最高的粒子）的来源引起了科学家们的许多推测，他们想到了包括从伽玛射线的爆发到衰变中的暗物质在内的一切。 |
| But researchers using the Pierre Auger Observatory in Argentina have found that the sources of the cosmic rays are not uniformly distributed across the sky. Instead, they appear to be coming from energetic supermassive black holes in the hearts of some galaxies, called Active Galactic Nuclei (AGN), which were also strongly suspected of being behind the rays. |
然而，研究人员利用阿根廷的皮埃尔·奥格天文台发现：宇宙射线源并不是均匀地分布于太空中的，相反，宇宙射线好象来自于一些星系中心区域的高能巨大黑洞。这些黑洞被称为活动星系核（AGN），研究人员曾经强烈地怀疑这些黑洞位于射线的背后。 |
| Study team member and Nobel laureate James Cronin of the University of Chicago called the finding, detailed in the Nov. 9 issue of the journal Science, a "fundamental discovery." |
研究小组成员、诺贝尔奖获得者芝加哥大学的詹姆士·克罗宁将这个发现称为一个“根本的发现”。该发现被详尽地记录在11月9日出版的《科学》杂志上。 |
| "The age of cosmic-ray astronomy has arrived," Cronin said. "In the next few years, our data will permit us to identify the exact sources of these cosmic rays and how they accelerate these particles." |
克罗宁指出：“宇宙射线天文学的时代已经到来了。在接下来的几年里，所掌握的数据资料将能够使我们找到这些宇宙射线的确切来源，并且可以让我们发现这些射线源是如何使粒子加速的。 |
| Cosmic particle accelerators |
宇宙粒子加速器 |
| Black holes are dense regions in space where gravity is so strong that nothing, not even light, can escape. Supermassive holes can have masses that are millions to billions times that of our sun. |
黑洞是太空中的高密度区域，引力极其强大，任何事物——哪怕是光，也无法逃脱其引力束缚。巨型黑洞的质量可以达到我们太阳质量的数百万倍至数十亿倍不等。 |
| Scientists think most galaxies, including our Milky Way, have supermassive black holes at their cores, but only a fraction of these are thought to be AGNs. Galaxies with AGNs seem to be those that suffered a collision with another galaxy or some other massive disruption in the last few hundred million years. |
科学家们认为，大多数星系包括我们银河系在内，在中心区域都拥有巨型黑洞，但是其中只有一小部分被认为是活动星系核。拥有活动星系核的星系，好象是那些在过去的几亿年中跟其他星系遭遇过碰撞的星系，或者是遭受过其他大规模破坏的星系。 |
| AGNs devour gas and dust swirling in from their host galaxies and, through processes that are still unclear, kick some particles out at nearly the speed of light. |
活动星系核吞噬着从其所在星系盘绕而入的气体与尘埃，同时将一些粒子以接近光速的速度“踢”出去，然而科学家们对这个过程尚不清楚。 |
| "If you had asked a theorist before the cosmic rays were discovered if anything could be accelerated to such high energies, they would say, 'No,'" said study team member Glennys Farrar of New York University. "So it's really amazing that nature does this." |
“在发现宇宙射线之前，如果你向一名理论家询问：是否可以将某物加速到如此之高的能量？他们会回答说：‘不可能！’”研究小组成员、纽约大学的格兰尼斯·法勒说，“所以说大自然做到了这一点，真是令人惊讶不已！” |
| Cosmic rays are thought to consist of protons and atoms stripped of their electrons. When one of these tiny particles smashes into Earth's upper atmosphere, it creates a cascade of secondary particles collectively called an air shower that can spread across 15 or more square miles (40 square kilometers) before hitting the ground. |
科学家们认为宇宙射线中包含质子和失去了电子的原子。当其中的一个微粒冲进地球大气上层的时候，就会产生二级粒子的喷流，统称为空气簇射。空气簇射可扩展到15平方英里或更大（相当于40平方公里）的范围，然后撞击到地面。 |
| In the study, the researchers traced 20 out of 27 high-energy cosmic-ray events to 20 known AGNs. The researchers say there is less than a one-in-100 chance that the correlation between the cosmic rays and AGNs is random. |
在这项研究中，研究人员将27个高能宇宙射线事件中的20个追溯到20个已知的活动星系核中。研究人员称，宇宙射线与活动星系核之间不规则相关的概率不过1%。 |
| Other sources? |
宇宙射线的其他来源 |
| They estimate the cosmic ray-spewing AGNs are located within 326 million light years of the Milky Way. "This is our local neighborhood in cosmic terms," said study team member Miguel Mostafa of the University of Utah. |
研究人员估计，喷出宇宙射线的活动星系核坐落在银河周围方圆3.26亿光年以内。“从宇宙的尺度来讲，这就相当于我们本地的近邻，”研究小组成员、犹他大学的米格尔·莫斯塔法说。 |
| Because not every cosmic ray particle was accounted for, the results leave room for other sources to exist, but it could also be they emanated from AGNs that haven't been discovered yet, Farrar told SPACE.com. |
法勒告诉《太空网》的记者：由于还没有将每一个宇宙射线粒子都解释清楚，该研究结果并不排除其他来源的存在，但是宇宙射线粒子也有可能源自尚未发现的活动星系核。 |
| And while the new study strongly links high-energy cosmic rays to AGNs, further studies will be needed to make the case air-tight. "It could be there is something that hangs around AGNs that are the true source," Farrar said. "What we know right now is if you find a [high-energy] cosmic ray, it is much more likely than random chance there will be AGN with it." |
尽管这项新研究将高能宇宙射线跟活动星系核密切地联系在一起，但仍将需要进一步研究，以便使该结果无懈可击。法勒说：“情况有可能是这样的：活动星系核附近的某处是宇宙射线的真正来源。我们现在所了解到的情况是：如果你发现了一条高能宇宙射线，它很可能跟活动星系核有关，而不大可能是随意的巧合。” |
