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The mass loss and death of massive stars

大质量恒星的质量损失和死亡

基本信息

批准号：
ST/F002181/1
负责人：
Jorick Vink
金额：
$ 31.43万
依托单位：
Armagh Observatory
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2008
资助国家：
英国
起止时间：
2008 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=ST%2FF002181%2F1
关键词：
mass loss death massive stars

项目摘要

Massive stars are important objects in astronomy for a number of reasons. Because of their brightness (up to a million times that of the Sun), they can be seen out to large distances, offering a glimpse of the Universe in our distant past. Massive stars possess strong outflows, and die spectacularly as supernovae and gamma-ray bursts - the most energetic cosmic explosions since the Big Bang. Due to these outflows and explosions, massive stars are thought to trigger star formation in galaxies throughout the Universe. They are also responsible for the chemical enrichment of the Universe. As the big bang only produced hydrogen and helium, the heavy elements, such as carbon, nitrogen, oxygen - critical for forming life - were synthesised in the cores of massive stars, and are returned to the surrounding medium through mass loss and explosions. The prime goal of the proposed project is to predict the amount of mass loss throughout the Universe, as it is this property that determines the life and death of a massive star. Although the life of solar-type stars is driven by the physical process of hydrogen burning in their cores, the life path of a massive star is largely dominated by mass loss. For instance, an object as massive as 60 times the mass of the Sun, will only end up with 6 times the mass of the Sun before it explodes. The amount of outflow however depends critically on the chemical environment. Our models have been shown to be successful in predicting the mass-loss properties in the Milky Way, but we now wish to extend our models to the early Universe. We will develop, test, and apply the new massive star models to map the strength of the outflow, their path to death, and the way they die. We will determine the final stellar masses and mass boundaries for the formation of neutron stars and black holes. The predictions will be extended to stars representative for conditions in the early Universe, when the cosmos contained no elements heavier than hydrogen and helium, and we will determine whether these objects make neutron stars or black holes and how they explode as supernovae or gamma-ray bursts. Current state-of-the-art models do not take mass-loss into account in a realistic way. Our models use the actual presence of the individual chemical elements - recently been shown to be of paramount importance for objects in the early Universe - and will bring the state-of-the-art to a new level. During the course of the programme, we will predict both the direct chemical enrichment by stellar outflows, and set constraints on their fate. Using both ingredients allows us - for the very first time to provide meaningful predictions for the chemical build-up of the early Universe.

大质量恒星是天文学中的重要对象，原因有很多。由于它们的亮度（高达太阳的一百万倍），它们可以在很远的地方被看到，让我们可以一睹遥远过去的宇宙。大质量恒星拥有强大的外流，并以超新星和伽马射线爆发的形式死亡-这是自大爆炸以来最具活力的宇宙爆炸。由于这些外流和爆炸，大质量恒星被认为触发了宇宙中星系中星星的形成。它们还负责宇宙的化学富集。由于大爆炸只产生氢和氦，重元素，如碳，氮，氧-形成生命的关键-在大质量恒星的核心合成，并通过质量损失和爆炸返回到周围的介质。该项目的主要目标是预测整个宇宙的质量损失量，因为正是这种性质决定了大质量星星的生与死。虽然太阳型恒星的生命是由其核心氢燃烧的物理过程驱动的，但大质量星星的生命路径在很大程度上是由质量损失主导的。例如，一个质量是太阳质量60倍的物体，在爆炸前只会有6倍的太阳质量。然而，流出量主要取决于化学环境。我们的模型已经被证明是成功的预测银河系的质量损失属性，但我们现在希望我们的模型扩展到早期宇宙。我们将开发、测试和应用新的大质量星星模型来绘制外流的强度、它们的死亡路径和死亡方式。我们将确定中子星和黑洞形成的最终恒星质量和质量边界。这些预测将扩展到代表早期宇宙条件的恒星，当时宇宙不包含比氢和氦更重的元素，我们将确定这些物体是否会形成中子星或黑洞，以及它们如何爆炸为超新星或伽马射线爆发。目前最先进的模型没有以现实的方式考虑质量损失。我们的模型使用单个化学元素的实际存在-最近被证明对早期宇宙中的物体至关重要-并将最先进的技术带到一个新的水平。在该计划的过程中，我们将预测恒星外流的直接化学浓缩，并对其命运设定限制。使用这两种成分使我们能够第一次为早期宇宙的化学物质积累提供有意义的预测。