The apocalypse is still on, apparently — at least in a galaxy about 3.5 billion light-years from here.看上去，末日依然不会首演——最少是在距离我们35亿光年的一个星系。Last winter a team of Caltech astronomers reported that a pair of supermassive black holes appeared to be spiraling together toward a cataclysmic collision that could bring down the curtains in that galaxy.过去的这个冬天，加州理工的一群天文学家公布论文称之为，一对超大质量黑洞或许在朝着灾难性撞击的轨迹运营，而这种撞击可能会宣告该星系的告一段落。The evidence was a rhythmic flickering from the galaxy’s nucleus, a quasar known as PG 1302-102, which Matthew Graham and his colleagues interpreted as the fatal mating dance of a pair of black holes with a total mass of more than a billion suns. Their merger, the astronomers calculated, could release as much energy as 100 million supernova explosions, mostly in the form of violent ripples in space-time known as gravitational waves that would blow the stars out of that hapless galaxy like leaves off a roof.他们的证据是这一星系中心的类星体PG 1302-102展现出出有了一种有规律的闪动。

研究人员马修·格雷厄姆(Matthew Graham)及其同事指出，这代表了一对总质量多达太阳10亿倍的黑洞在相互环绕着，南北丧生。根据他们的估计，二者拆分也许可以释放出来1亿颗超新星发生爆炸的能量，多数展现出为“引力波”。这种时空中的激烈涟漪不会让星体从那莫名其妙的星系中涌出，只不过就是指屋顶上刮走树叶。Now a new analysis of the system by Daniel D’Orazio of Columbia University and his colleagues has added weight to that conclusion. Mr. D’Orazio, a graduate student, and his colleagues Zoltan Haiman and David Schiminovich propose that most of the light from the quasar is coming from a massive disc of gas surrounding the smaller of the two black holes.现在，哥伦比亚大学(Columbia University)的丹尼尔·德奥拉齐奥(Daniel D’Orazio)及其同事对这一星系展开的新分析，给上述结论加添了份量。

研究生德奥拉齐奥和同事佐尔坦·海曼(Zoltan Haiman)、戴维·希米诺维奇(David Schiminovich)明确提出，这颗类星体收到的光多数来自环绕着其中一个较小黑洞的粗壮的白矮星盘。As the black holes and their attendant discs swing around each other at high speeds, the light from the disk that is coming toward us gets a boost from relativistic effects – a so-called Doppler boost — the same way a siren gets louder and more high-pitched as it approaches, giving rise to a periodic increase in brightness every five years.这两个黑洞及其白矮星盘互相高速旋转时，来自这个白矮星盘的光线在对着地球的方向会因相对运动产生的多普勒效应而强化——只不过对面驶向的火车鸣笛声会显得更加大声、更加下颚一样——令其它间隔五年不会周期性地减小亮度。The Columbia astronomers’ model predicts that the variation would be two or three times greater in ultraviolet light than in visible light. And that is exactly what they found when they compared archival data from the Hubble Space Telescope and NASA’s Galex space telescope to the visible-light data previously analyzed by Dr. Graham’s group.哥伦比亚大学的这三名天文学家创建的模型预测，其中紫外线的变化不会比红外线明显。

他们拿走哈勃太空望远镜和美国航空航天局的星系进化探测器(Galex)的历史数据，与格雷厄姆团队之前分析的红外线数据展开核对，找到结果正好与预测相符。“What’s big is that the Doppler boost is inevitable,” Dr. Haiman said in an email. Given reasonable assumptions about the masses of the two black holes, their model predicts the right ultraviolet data. “This is rare in ‘messy’ astronomy,” he said, “to have an indisputable clean effect, which explains the data.” Follow-up observations of ultraviolet and visible light emissions in the coming years could help the clinch the case, the authors said. Their paper was published on Wednesday in the journal Nature.“其中的重大意义在于，这不能是多普勒效应，”海曼博士通过电子邮件拒绝接受专访时回应。只要得出有关这两个黑洞质量的合理假设，他们的模型就能预测出精确的紫外线数据。

“在‘恐慌’的天文学研究中，很难看见有一个没什么争议的明晰理论需要对数据作出说明，”他说道。三名研究人员回应，未来几年对紫外线和红外线电磁辐射的跟踪仔细观察或将不利于得出结论佐证的结论。他们的论文于本周三公开发表在《大自然》杂志(Nature)上。

Their model suggests that the black holes are orbiting each other at a distance of some 200 billion miles, less than a tenth of a light-year, a cosmic whisker. At that distance the black holes would be rapidly losing energy by radiating gravitational waves and could spiral together into the final bang in as little as 100,000 years, Dr. Haiman said, depending on their relative masses.他们的模型表明，两个黑洞在互相环绕着，之间的距离大约为2000亿英里，将近0.1光年。这在宇宙中堪称密切连接。海曼称之为，距离这么将近的话，这两个黑洞应该以收到引力波的形式较慢失去能量，并且可能会最慢在10万年后最后撞。“Basically, the more massive the holes, the faster gravitational waves drive them together, and we do require them to be as massive as allowed to be,” he said in an email. For their model to hold up, the larger of the black holes has to be a billion solar masses or more.“基本上，双黑洞质量越大，引力波将他们纳到一起的速度就越慢，而我们的研究的确假设他们在容许的范围内质量尽量地大，”他在邮件中写到。

他们的模型要想要正式成立，双黑洞中较小的那个的质量最少得相等于10亿个太阳。E. Sterl Phinney, a Caltech astronomer and expert on supermassive black holes currently on sabbatical at Radboud University in the Netherlands, agreed that Dr. Haiman’s model explains the quasar variations. “So Occam’s razor makes it attractive,” he said in an email, referring to the long-held principle that physicists should adopt the simplest theory that fits the facts.加州理工的天文学家E·施特尔·菲尼(E. Sterl Phinney)是超大质量黑洞领域的专家，目前在荷兰的内梅亨大学(Radboud University)休学术假。他指出海曼的模型需要说明这颗类星体的闪动。

“奥卡姆剃刀让它讨人喜欢一起，”他在拒绝接受专访的电子邮件中写到。奥卡姆剃刀是一个由来已久的原则，指出物理学家们应当使用最简练的理论来说明事实。But it was surprising, he said, to find a pair of supermassive black holes that have gotten so close.不过他也回应，寻找距离如此相似的一对超大质量黑洞令人车祸。

Black holes, predicted by Albert Einstein’s general theory of relativity, the prevailing theory of gravity, are objects so dense that not even light can escape from them. In effect they are bottomless pits in space-time. Every galaxy of note seems to have a supermassive black hole, weighing millions or billions of times as much as the sun, burping sparks of half-eaten stars and gas.阿尔伯特·爱因斯坦(Albert Einstein)的广义相对论是有关引力的权威理论，其中预测了黑洞的不存在。黑洞十分颗粒，实在太光线都无法借此脱逃。它们实质上是时空中的无底洞。

每个最重要星系或许都有一个质量为太阳无数倍的超大黑洞，大大电磁辐射出正被毁灭的星体和气体的闪光光线。When galaxies merge, their resident black holes are sent into forced marriages, orbiting each other. But without gravitational interactions with stars or interstellar gas, supermassive black holes can’t get close enough to each other to go into a rapid death spiral, a situation known as the “final parsec” problem. (A parsec is the astronomical standard of distance, 3.26 light-years.)当星系拆分的时候，各自的黑洞不得不拴在一起，互相环绕着运动。不过，如果没与星体或星际气体之间的互相机车，超大质量黑洞无法附近到能很快南北撞击的地步，而这种现象被称作“最后的秒差距”问题（秒差距是天文学距离单位，1秒差距相等3.26光年）。

So, as Dr. Phinney explained, unless hundreds of millions of solar masses of gas accompany the black holes, “there are not very convincing ways of getting them to smaller separations” like the black holes in PG 1302-102.因此，正如菲尼说明的那样，除非双黑洞周围有数亿太阳质量的气体，“没令人信服的办法来让它们的距离增大”到PG 1302-102的两个黑洞那么将近的地步。At least that is the theory. If such systems are common, Dr. Phinney said, the gravitational waves emanating from them should sweep the universe and disrupt the timing of signals from pulsars, an effect that could be detected within the next few years by various ongoing programs to time pulsars.最少理论上如此。

菲尼称之为，假如这种系统很少见，那么借此收到的引力波应当席卷整个宇宙，阻碍到脉冲星信号的节奏，那么在未来几年里，目前正在展开的多个观测脉冲星时间的项目就应当可以仔细观察到这一现象。“A scientific theory is only as good as the tests which it has passed,” Mr. D’Orazio said in an email. Although general relativity has passed all of the observational and experimental tests thrown at it so far, some of its predictions can only be tested in the most extreme gravitational environments, namely black holes. “Detection of gravitational waves,” he said, “is a direct probe of this region and hence the secrets of gravity.”“科学理论的正确性是由它遭受的考验要求的，”德奥拉齐奥在邮件中回应。尽管广义相对论遭受寄居了迄今为止所有与之涉及的实验和观测的考验，但该理论蕴藏的一些预测不能在最极端的引力环境中检验，也就是黑洞。“观测引力波是对这种区域的必要探究，继而也是对引力的奥秘的必要探究，”他说道。

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