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

“计算行星、恒星和星系的形成：弥合尺度”

• 批准号: 298470-2012
• 负责人: Wadsley, James
• 金额: $ 2.99万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=571497
• 关键词: Computational; Planet; Star; Galaxy; Formation

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. We can see stars form today in our Milky Way in clouds of gas and dust weighing up to a million Suns. However, to get a correct picture of the early universe we need to understand the process in detail, so that we can know how stars form when the amounts of gas, dust and radiation are much greater or much lower. We are able to create giant clouds filled with twisted filaments compressed from supersonic gas so tenuous it would be called a vacuum on earth. These filaments break up into glowing young stars like pearls on a string just as they do in stellar nurseries on the sky. We follow these studies to the logical extreme -- heavy gas disks containing a new star where planets too can form. We have been able to form exotic extra-solar planetary systems where massive planets much larger than Jupiter orbit at great distances from their stars as observed by Canadian astronomers.

计算机模拟使天文学家看到星系的梦想成为可能，这些星系变化如此缓慢，它们以美丽但静止的星云的形式固定在天空中，由数十亿颗恒星照亮，在他们眼前演变。 当加速到数百万年的瞬间，星系是动态的地方，旋转的漩涡，恒星不断诞生和爆炸性死亡。 我们现在可以人工生成盘状星系，这些星系具有闪烁的气体、尘埃和恒星的精致螺旋图案，几乎与天空中附近的那些相同。 挑战在于将事情发挥到极致：模拟星系撞击在一起，产生巨大的新星爆发，并将物质推入超大质量黑洞，这些黑洞本身的大小与隐藏在天空中几乎每个星系中间的小星系一样。 这些合并在早期宇宙中很常见，当时星系是更暴力的地方，更像是风暴破坏的云而不是螺旋盘，并且充满了远高于我们银河系今天所经历的气体，尘埃和辐射水平。 今天我们可以看到银河系中的恒星形成，它们是由气体和尘埃组成的云，重达100万个太阳。 然而，为了正确了解早期宇宙，我们需要详细了解这个过程，这样我们才能知道当气体、尘埃和辐射的量大得多或少得多时，恒星是如何形成的。 我们能够创造出巨大的云层，里面充满了由超音速气体压缩而成的扭曲的细丝，这种气体非常稀薄，在地球上被称为真空。 这些丝状物分裂成发光的年轻恒星，就像串在绳子上的珍珠一样，就像它们在天空中的恒星托儿所一样。 我们遵循这些研究到逻辑的极端--含有一颗新星星的重气体盘，行星也可以在那里形成。 我们已经能够形成奇异的太阳系外行星系统，在这些系统中，加拿大天文学家观测到比木星大得多的大质量行星在距离其恒星很远的地方运行。