科学美国人60秒 银河系的历史成为焦点（在线收听）

The History of the Milky Way Comes Into Focus

银河系的历史成为焦点

Christopher Intagliata: When you look up at the Milky Way, you're gazing at the galactic equivalent of Rome. A metropolis of stars, with layers upon layers of history—just like The Eternal City. So says the astronomer Hans-Walter Rix.

Christopher Intagliata：当你仰望银河系时，你正在凝视罗马的银河系。 星辰大都会，层层叠叠的历史——就像永恒之城。 天文学家汉斯-沃尔特·里克斯如是说。

Hans-Walter Rix: There were glory days, there were disasters, and all of these things kind of happen in the life of galaxies. And the Milky Way is just the one galaxy where we can look at star by star so you can kind of see individual episodes in actual detail.

Hans-Walter Rix：有过辉煌的日子，也有过灾难，所有这些事情都发生在星系的生活中。 银河系只是我们可以逐星观察的一个星系，因此您可以查看各个情节的实际细节。

Intagliata: Now Rix and a colleague at the Max-Planck Institute for Astronomy in Germany have indeed gone star by star… determining the ages of nearly a quarter million stars in the Milky Way. That work has allowed them to reconstruct some of the major life events in the galaxy's evolution, over its 13 billion years of existence.

Intagliata：现在，Rix 和德国马克斯-普朗克天文学研究所的一位同事确实逐星进行了研究……确定了银河系中近 25 万颗恒星的年龄。 这项工作使他们能够重建银河系演化中的一些主要生命事件，在其存在的 130 亿年中。

Rix: What it showed is that indeed the youth and childhood of the Milky Way was turbulent… but actually afterwards we've lived an enormously sheltered life compared to most other galaxies. Gas drizzled in, and the suburbs grew peacefully and sprawled.

Rix：它表明银河系的青年和童年确实是动荡的……但实际上，与大多数其他星系相比，我们过着非常隐蔽的生活。 煤气下着毛毛细雨，郊区平静地蔓延开来。

Intagliata: The astronomers say that the galaxy's thick disk began to form about 13 billion years ago, just 800 million years after the Big Bang. Then, around 11 billion years ago, a cataclysmic collision occurred: the Gaia-Enceladus satellite galaxy crashed into the Milky Way.

Intagliata：天文学家说，银河系的厚圆盘大约在 130 亿年前开始形成，也就是大爆炸之后的 8 亿年。 然后，大约 110 亿年前，发生了一场灾难性的碰撞：盖亚-土卫二卫星星系坠入了银河系。

Rix: And just at the same time, there was a huge burst of star formation, or a large increase of star formation in our own Milky Way. And that suggests—doesn't prove—that the perturbance that this in-falling satellite created, caused a lot of gas that was in our Milky Way to form stars.

Rix：就在同一时间，恒星形成的巨大爆发，或者说我们银河系中的恒星形成大幅增加。 这表明——并不能证明——这颗坠落的卫星产生的扰动导致我们银河系中的大量气体形成了恒星。

Intagliata: The details are in the journal Nature. [Maosheng Xiang & Hans-Walter Rix, A time-resolved picture of our Milky Way’s early formation history]

Intagliata：详情见自然杂志

Now, none of this is a total surprise—people have simulated the Milky Way's formation before.

Rix: So I would say really what our work has done is it just shows it clearly a long-suspected picture is coming into focus.

现在，这一切都不足为奇——人们以前曾模拟过银河系的形成。

Rix：所以我想说的是，我们的工作所做的只是清楚地表明，一幅长期怀疑的画面正在成为焦点。

Intagliata: In other words—this work lays out a more definitive playbill of the acts in this galactic drama.

Intagliata：换句话说，这部作品为这部银河剧中的行为制定了更明确的剧本。