"Computational Planet, Star and Galaxy Formation: Bridging the Scales"

计算机模拟使天文学家看到星系的梦想能够在他们眼前进化。星系变化如此之慢，以至于它们看起来像是被数十亿颗恒星照亮的美丽但静止的星云形式固定在天空中。当速度加快，数百万年后的瞬间，星系是动态的地方，在那里恒星不断地诞生和爆炸性死亡的漩涡。我们现在可以人工生成具有闪闪发光的气体、尘埃和恒星的微妙螺旋图案的盘状星系，这些图案与附近天空中的几乎完全相同。挑战是将事情推向极端：在星系相互碰撞时对它们进行建模，创造出巨大的新恒星爆发，并将物质驱动到超大质量黑洞中，这些黑洞本身的大小相当于隐藏在天空中几乎每个星系中间的小星系。这种合并在早期宇宙中很常见，当时的星系要猛烈得多，更像是风暴肆虐的云层，而不是螺旋盘，气体、尘埃和辐射的饱和水平远远高于我们银河系今天所经历的水平。

Computer simulations enable the astronomer's dream of seeing galaxies, that change so slowly they appear fixed on the sky in the form of beautiful but static nebulae lit by billions of stars, to evolve before their very eyes. When sped up so that millions of years pass in moments galaxies are dynamic places, swirling vortices where stars are constantly being born and explosively dying. We can now artificially generate disk galaxies with delicate spiral patterns of sparkling gas, dust and stars almost identical to those nearby in the sky. The challenge is to take things to the extreme: to model galaxies as they smash together and create giant bursts of new stars and drive material into super-massive black holes themselves the size of small galaxies lurking in the middle of nearly every galaxy in the sky. These mergers are commonplace in the early universe when galaxies were far more violent places, more like storm wracked clouds than spiral disks and saturated with levels of gas, dust and radiation far above what our Milky Way Galaxy experiences today.