人类初次“看到”引力波 总算找到金子的源头了
First-seen neutron star collision creates light, gravitational waves and gold

来历: CNN、商业内情网、新华社、科技日报

10月16日22时,世界地理界宣告一次新的科学发展:初次直接勘探到双中子星并合引力波及其随同的电磁信号。这标志着人类前史上第一次运用引力波地理台和其他望远镜观测到同一天体物理事情,预示着地理学研讨进入“多信使”阶段。

人类初次“看到”引力波

全球多国科学家16日同步举办新闻发布会,宣告人类第一次直接勘探到来自双中子星兼并的引力波,并一起“看到”这一壮丽世界事情宣告的电磁信号。

美国国家科学基金会、美国LIGO等供给的效果图显现两个并合中的中子星。新华社发

On Monday, scientists who won a Nobel Prize for their discovery of gravitational waves announced the first detection of the collision of two neutron stars.

10月16日,因发现引力波而取得诺贝尔奖的科学家团队宣告,他们初次勘探到了中子星兼并。

Astronomers detected the merger from 130 million light-years away, in the galaxy NGC 4993, on the morning of August 17.

地理学家在8月17日晨间观测到的此次兼并来自1.3亿光年之外的NGC 4993星系。

The team alerted astronomers all over the world to the event right after it happened, helping them point telescopes directly at the scene of the crash.

在勘探到这一地理事情后,科学家团队提示全球的地理学家观测这一现象,协助他们把望远镜对准兼并现场。

此次引力波事情具有极为重要的含义,地理学家运用了很多地上和空间望远镜进行观测,构成了一场地理学前史上极为稀有的全球规划的联合观测。不过,在引力波事情发作时,仅有4台X射线和伽马射线望远镜成功监测到迸发天区,我国的“慧眼”望远镜便是其中之一。

慧眼望远镜示意图。来历:科技日报

依据勘探记载,科学家恢复出整个事情发作的进程:在间隔地球1.3亿光年的长蛇座星系NGC4993中,两颗中子星相互绕转。在并合前约100秒时,它们相距400公里,每秒钟相互绕转12圈,并向外辐射引力波。它们越转越近,直至终究磕碰在一起,构成新的天体,并宣告电磁辐射。

双中子星并合后宣告短伽玛暴和巨新星辐射的示意图 来历:科技日报

The collision created the first observed instance of a single source emitting ripples in space-time, known as gravitational waves, as well as light, which was released in the form of a two-second gamma ray burst.

经过这次兼并,科学家初次观测到太空中单源发射的引力波,并观测到了以两秒钟的伽马射线暴方法释放出的可见光。

It is being hailed as the first known instance of multi-messenger astrophysics: one source in the universe emitting two kinds of waves, gravitational and electromagnetic.

这预示着天体物理学初次进入多信使阶段:世界中的同一来历发射出两种方法的波,引力波和电磁波。

你戴的金戒指来自中子星磕碰?

我国紫金山地理台副研讨员金志平参加的世界团队,经过对此次引力波光学信号的观测和光谱分析,初次供给确凿依据证明,中子星兼并是世界中金银等元素的首要来历。金志平说:“这便是世界中的‘巨型黄金制造厂’。”

双中子星兼并图解。(来历:NASA)

These images revealed a radioactive soup giving birth to unfathomable amounts of platinum, gold, and silver — not to mention elements like the iodine found in our bodies, the uranium in nuclear weapons, and the bismuth in Pepto-Bismol — while shooting those materials deep into space.

观测图画显现出了两个中子星的放射性磕碰场景,而这也发生了数量巨大的铂、金和银,以及咱们身体中的碘、核武器中的铀、可以减轻肠胃不适的铋。中子星兼并将这些物质四散进世界深处。

The two neutron stars most likely merged to form a black hole, though the tiny bit of neutron star that escaped — and formed new elements — could get recycled into planets like Earth where aliens may eventually dig up the metals as we have.

两个中子星最或许兼并成一个黑洞,但兼并中四散出的碎块会构成新的元素,循环进入相似地球的星体,或许外星人正像咱们相同发掘这些金属矿产。

什么是“引力波”?

引力波是由黑洞、中子星等磕碰发生的一种时空涟漪,宛如石头丢进水里发生的波纹。百年前,爱因斯坦广义相对论预言了引力波的存在,但直到2015年人类才初次勘探到引力波,3名美国科学家因而取得本年的诺贝尔物理学奖。

双中子星并合进程中的物质抛射和喷流构成数值模仿 来历:科技日报

Gravitational waves were first directly detected two years ago, proving Albert Einstein's theory of general relativity, and recently, three scientists were awarded the Nobel Prize in Physics for their work on that first detection. Those gravitational waves were the result of two black holes colliding, and the signal lasted for only a fraction of a second. Because black holes don't emit light, these waves were invisible and only "heard" as thumps.

引力波于两年前初次被发现,证明了爱因斯坦的广义相对论。最近,三位科学家因初次勘探到引力波被颁发诺贝尔物理学奖。他们成功勘探到来自于两个黑洞兼并的引力波信号,信号仅继续几毫秒。由于黑洞并不发射出光,因而引力波不行见,只能以急速跳动的方法被“听到”。

引力波示意图 来历:NASA

此次观测为何含义特殊?

这是人类第五次勘探到引力波,但是科学界的振奋之情乃至不亚于第一次勘探到引力波时。由于与之前被勘探到的四个引力波信号不同,这次勘探到的引力波信号GW170817来自1.3亿光年外两颗并合的中子星,并且科学家第一次一起观测到了引力波及其电磁对应体,以及科学家预言的巨新星现象。

激光干与引力波地理台(LIGO) 来历:科技日报

1. For the first time, telescopes and gravitational wave observatories together witnessed the same astronomical event.

这是人类前史上第一次运用电磁波望远镜和引力波地理台一起观测到同一个天体物理事情。

2. This is the first time gravitational waves from the merger of binary neutron stars have been observed.

这是初次观测到双中子星兼并发生出引力波。

3. This observation is the first to definitively identify binary neutron star collisions as a source of short gamma-ray bursts. Theorized for many years, this is the first direct link between those phenomena.

这次观测初次为中子星兼并可发生伽马射线短暴给予了确凿依据。这一理论已有多年前史,而此次观测初次证明了这两种现象之间有直接联络。

4. This discovery is the first verification of a "kilonova" explosion, confirming binary neutron star collisions as one source for the universe's heaviest elements, such as gold and uranium.

这次发现初次证明了“千新星”爆破,确认了双中子星兼并是世界中最重的元素的来历之一,比方金和铀。

5. This is the first binary neutron star pair confirmed outside of our own Milky Way galaxy, and this is the closest to Earth that astronomers have seen a gamma ray burst.

这是银河系外初次得以证明的一对中子星,也是地理学家观测到伽马射线暴间隔地球最近的一次。

6. The gravitational wave signals from GW170817 have enabled scientists to measure the expansion rate of the universe in a completely new way.

来自此次GW170817观测的引力波使科学家可以用全新的方法丈量世界的膨胀率。

7. The partnership between LIGO and Italy-based Virgo allowed telescopes to rapidly turn their attention towards the area of sky where the neutron stars collided.

激光干与引力波地理台(LIGO)和意大利的处女座引力波勘探器(Virgo)让很多望远镜敏捷调转方向,对准这一片天空,观测两个中子星兼并。

8. This event presents the strongest evidence to date for the detection of a gamma-ray burst off-axis, which means the cone emission from the explosion is not pointed directly at Earth.

此次观测为伽马射线暴轴偏移供给了有史以来最强有力的依据,也便是说伽马射线暴发生的锥状发射不是直接对准地球的。

9. The gravitational waves and light waves arrived within seconds of each other, suggesting they may travel at the same speed and confirming a prediction of Albert Einstein. The difference in detection time is likely a reflection of what happens during the explosion process.

引力波和光波抵达地球的时刻相差只要几秒钟,这意味着两者传播速度相同,证明了爱因斯坦的猜测。勘探时刻的差异很或许反映出兼并进程中发作了什么。

10. Only gravitational wave observatories can directly detect unexploded binary neutron stars outside of our local galactic neighborhood, or directly observe the stars pre-collison, albeit only briefly before impact.

只要引力波地理台可以勘探到银河系外未爆破的双中子星,或许直接观测兼并前的双中子星,不过只是在兼并或爆破前很短的时刻内。