中子星周围的时空扭曲（图）   

中子星及其外侧高速旋转的高温气体圆盘

                                   Einstein's Warping Found Around Neutron Stars

Einstein's predicted warping of space-time has been discovered around neutron stars, the most dense observable matter in the universe.	在中子星周围发现了爱因斯坦所预测的时空扭曲。中子星是宇宙中密度最大的可观测物质。
The warping shows up as smeared lines of iron gas whipping around the stars, University of Michigan and NASA astronomers say. The finding also indicates a size limit for the celestial objects.	密歇根大学和美国国家航空航天管理局（NASA）的天文学家们说，这种扭曲表现为中子星周围含铁气体快速旋转所造成的模糊线路。这个发现还可以用来测定中子星的体积限度。
The same distortions have been spotted around black holes and even around Earth, so while the finding may not be a surprise, it is significant for answering basic questions of physics, said study team member Sudip Bhattacharyya of NASA's Goddard Space Flight Center in Greenbelt, Md. and the University of Maryland, College Park. "This is fundamental physics," Bhattacharyya said. "There could be exotic kinds of particles or states of matter, such as quark matter, in the centers of neutron stars, but it's impossible to create them in the lab. The only way to find out is to understand neutron stars."	研究小组成员、美国国家航空航天管理局戈达德太空飞行中心（Goddard Space Flight Center）的苏迪普·班特查里亚指出：在黑洞周围，甚至在地球周围也曾发现同样的扭曲，所以说这个发现可能并不那么令人吃惊，但是对于解决最基本的物理问题具有重大的意义。班特查里亚说：“这是基础物理学问题。在中子星的核心可能存在怪异的粒子或奇特的物质状态，如由夸克构成的物质。但在实验室是不可能创造出这些物质的，所以如果想搞明白，唯一的办法就是要了解中子星。”
Neutron stars can pack more than a sun's worth of material into a city-sized sphere. A few cups of neutron-star stuff would outweigh Mount Everest. Astronomers use these collapsed stars as natural laboratories to study how tightly matter can be crammed under the most extreme pressures nature can offer.	中子星可以将质量相当于不下一颗恒星的物质包容在一座城市大小的球体中，几茶杯中子星上的物质重量就会超过珠穆朗玛峰！天文学家们将这些塌缩的恒星当作天然实验室，来研究在大自然可提供的极度压力下，物质可以达到多大的密度。
To even begin to address the mystery of what lies within these dying stars, scientists must accurately and precisely measure their diameters and masses.	科学家们要想揭开这些垂死恒星的内部之谜，首先要必须精确地测量它们的直径和质量。
In two concurrent studies, astronomers used the European Space Agency's XMM-Newton X-ray Observatory and the Japanese/NASA Suzaku X-ray to survey three neutron-star binaries: Serpens X-1, GX 349+2 and 4U 1820-30. They also studied the spectral lines from hot iron atoms that whirl around in a disk just beyond the neutron stars' surfaces at speeds reaching 40 percent light speed.	在同时进行的两项研究中，天文学家们利用欧洲航天局的XMM-牛顿X射线望远镜和日本与美国合作制造的“朱雀号”X射线望远镜观测了三对中子双星：巨蛇座X-1，GX 349+2和4U 1820-30。他们还研究了紧靠在中子星表面外侧的高温铁原子光谱线。这些铁原子在一个圆盘中旋转，速度高达光度的40%。
Normally, the measured spectral line for the superheated iron atoms would show up as a symmetrical peak. However, their results showed a skewed peak that was indicative of distortion due to relativistic effects. The extremely fast motion of the gas (and the related powerful gravity), they say, causes the line to smear, shifting it to longer wavelengths.	通常，所测得的超高温铁原子光谱线会显示出一个均匀的尖顶。然而，此处的结果是显示了一个歪斜的尖顶，这表明是由于相对论效应所造成的扭曲。研究人员指出，气体的超高速运动，外加上述的强大引力，使得旋转线路模糊不清，并使其波长变得更长。
The measurements allowed them to determine maximum star size. "We're seeing the gas whipping around just outside the neutron star's surface," said XMM-Newton team member Edward Cackett of the University of Michigan. "And since the inner part of the disk obviously can't orbit any closer than the neutron star's surface, these measurements give us a maximum size of the neutron star's diameter." He said the neutron stars can be no larger than about 20.5 miles (33 kilometers) across.	这些测量方法能够使研究人员确定中子星的最大体积。XMM-牛顿研究小组成员、密歇根大学的爱德华·卡克特说：“我们观察到气体紧靠在中子星表面的外侧旋转。很明显，由于圆盘内侧旋转时靠得再近也无法进入中子星表面以内，这样这些测量使我们获得了中子星的最大直径。”他指出，这些中子星的直径不可能超过20.5英里（33公里）。
The XMM-Newton paper was published in the Aug. 1 issue of Astrophysical Journal Letters. The other paper has been submitted for publication in the same journal.	XMM-牛顿研究小组的论文发表在8月1日的《天体物理学杂志通讯》上；另一篇论文已经提交到同一份杂志，以待发表。