Massive stars as cosmic engines

作为宇宙引擎的大质量恒星

• 批准号: 615-2011
• 负责人: Moffat, Anthony
• 金额: $ 3.5万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=512992
• 关键词: Massive; stars; cosmic; engines

Massive stars comprise all stars initially above 8 solar masses (Msun). Up to about 100 Msun they burn elements in successive, ever-hotter central shells right through to iron, before becoming core-collapse supernovae, leaving a neutron star or black hole remnant depending on the initial mass. Above about 100 Msun they burn only to oxygen in their cores before becoming pair-instability supernovae with complete disruption. Since the radiative output of a normal star goes roughly as the cube of its mass, a single 100 Msun star matches the total radiation output from a million Suns. Above some 20 Msun, massive stars further distinguish themselves by their strong winds, ranging up to a billion times that of the Sun. Thus, although rare and short-lived, massive stars deliver huge quantities of mostly lethal UV radiation and enriched material to the interstellar medium, ready to build more stars and planets like Earth. This was especially important in the early Universe, when the first stars formed were probably all very massive. Clearly, massive stars dominate the ecology of the Cosmos, yet many of their basic parameters remain elusive.

大质量恒星包括所有初始质量超过8个太阳质量（Msun）的恒星。直到大约100兆太阳的时候，它们在连续的、越来越热的中心壳层中燃烧元素，直到铁，然后变成核心坍缩的超新星，根据初始质量留下中子星星或黑洞残余。 超过100 Msun时，它们只会在核心燃烧成氧气，然后变成完全分裂的对不稳定超新星。由于一颗正常星星的辐射输出大约是其质量的立方，因此一颗100兆太阳的星星相当于一百万个太阳的总辐射输出。 在大约20 Msun以上，大质量恒星通过它们的强风进一步区分自己，范围高达太阳的十亿倍。 因此，虽然稀有且寿命短暂，但大质量恒星向星际介质提供大量致命的紫外线辐射和浓缩物质，准备建造更多像地球一样的恒星和行星。 这在早期宇宙中尤其重要，当时形成的第一批恒星可能都非常巨大。显然，大质量恒星主宰着宇宙的生态，但它们的许多基本参数仍然难以捉摸。