Accretion-related feedback: star formation, black hole accretion, explosive transients

吸积相关反馈：恒星形成、黑洞吸积、爆炸瞬变

• 批准号: RGPIN-2017-06791
• 负责人: Matzner, Christopher
• 金额: $ 2.62万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712458
• 关键词: Accretion; related; feedback; star; formation

Many of the most important problems in astrophysics arise because of energetic feedback the coupling of energy from a compact engine (like a star, neutron star, or black hole) into its own fuel supply (a stellar envelope, or a collapsing molecular cloud, or a spiral galaxy). The projects within this proposal are designed to sort out feedback interactions in several key contexts. First, most of the stars created within spiral galaxies like ours are the product of clustered star formation, in which hundreds to thousands of stars are born together in a tumultuous, turbulent collapse. Here, starlight heats and pressurizes the gas, altering the masses of later stellar generations; at the same time, winds, jets, and light (and ultimately supernovae) work to clear the mass reservoir, allowing the cluster to disperse. However, current estimates set these effects too weak to clear matter effectively; but there is evidence it must be. Two of the proposed projects will improve upon these estimates with more sophisticated studies of radiation transfer and stellar wind evolution within the cluster-forming zone; a third analyzes observations of a giant cluster-forming site in the Milky Way. Second, the field of gravity wave astronomy is only a year old, but detections will soon shed much light on the origins of stellar-mass black hole binaries. Almost certainly the outcome of stellar collapse, a fraction of these are born in the brilliant gamma-ray bursts thought to involve a collapsing, rapidly rotating massive star. Moreover, one hole may plunge through the envelope of its companion star (in a leading proposed scenario). In either case, an accretion disk forms around the black hole and, since photons are trapped, a mass-loaded wind will emanate from the disk. Energetic feedback from these winds has a strong effect on the star that feeds the disk, dramatically altering the outcome in ways I intend to predict and simulate. Third, modern astronomical surveys are capable of tracking time-variable events like supernovae, gamma-ray bursts, and related phenomena like stellar outbursts and tidal disruption events, many of which result from the reaction of a star's envelope to energy output from its core. I and my students will work to quantify poorly-understood classes of explosions, including non-spherical supernovae and shock-driven outbursts that do not destroy the star, while also analyzing the data of a current survey and preparing for much larger ones.

天体物理学中许多最重要的问题都是由于能量反馈而产生的，即来自紧凑引擎（如恒星、中子星或黑洞）的能量耦合到其自身的燃料供应（恒星包层、坍缩的分子云或螺旋星系）中。 该提案中的项目旨在整理几个关键环境中的反馈交互。 首先，像我们这样的螺旋星系中产生的大多数恒星都是星团形成的产物，其中成百上千颗恒星在混乱、湍流的塌缩中一起诞生。 在这里，星光对气体进行加热和加压，改变了后来恒星的质量。与此同时，风、喷流和光（最终是超新星）会清除质量库，使星团分散。 然而，目前的估计认为这些影响太弱，无法有效地清除物质；但有证据表明一定如此。 其中两个拟议项目将通过对星团形成区内的辐射传输和恒星风演化进行更复杂的研究来改进这些估计；第三部分分析了对银河系中一个巨大星团形成地点的观测结果。 其次，引力波天文学领域只有一年的历史，但探测很快就会为恒星质量黑洞双星的起源提供更多线索。 几乎可以肯定，这是恒星塌缩的结果，其中一小部分诞生于明亮的伽马射线爆发，人们认为这些爆发涉及一颗正在塌缩、快速旋转的大质量恒星。 此外，一个洞可能会穿过其伴星的外壳（在一个主要的提议场景中）。 无论哪种情况，吸积盘都会在黑洞周围形成，并且由于光子被捕获，吸积盘将从吸积盘中发出。 这些风的能量反馈对为盘提供能量的恒星产生了强烈的影响，以我打算预测和模拟的方式极大地改变了结果。 第三，现代天文勘测能够跟踪超新星、伽马射线爆发等随时间变化的事件，以及恒星爆发和潮汐瓦解事件等相关现象，其中许多现象是恒星包层对其核心能量输出的反应造成的。 我和我的学生将致力于量化人们知之甚少的爆炸类型，包括非球形超新星和不会摧毁恒星的冲击驱动的爆发，同时分析当前调查的数据并为更大的爆炸做准备。